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00:01Deep in the Egyptian desert there stands an exceptional structure, the Bent Pyramid,
00:06an enigmatic and unique edifice that has survived the centuries.
00:11It was the first building in the world to reach a height of over 100 meters.
00:17No one had ever built a pyramid of such gigantic dimensions.
00:21The pharaoh, to emphasize his power to his people, was building a very big structure.
00:26Anyone familiar with the famous pyramids at Giza immediately notices something different about this one.
00:34It's the only one on Earth that has this odd shape.
00:38This stone colossus was the work of one of the most powerful pharaohs in Egyptian history, Snefru.
00:45But the odd silhouette of his tomb may have been caused by an accident,
00:49the traces of which might still be visible on the inside.
00:52Major fissures started appearing in the structure. Everything was not well.
00:57I think Snefru sincerely wanted to build a true pyramid with straight sides.
01:02To uncover the secrets of the Bent Pyramid, we decided to look for answers at the very heart of its
01:07structure.
01:09Could its fascinating passageways provide us with clues?
01:12What secrets are its various chambers as enormous as cathedrals hiding?
01:17To shed light on all these mysteries, our scientists were granted permission to venture inside Egypt's most iconic pyramids with
01:25a latest generation laser scanner.
01:28It's quite tight in here. I'll try and worm my way through it.
01:33Using this procedure, they're able to create a very precise digital copy of the inside of the structure.
01:39With a few clicks, we can perform measurements that would be extremely hard to carry out on the ground.
01:44These tools will let our experts discover new clues in this ongoing scientific investigation which began 200 years ago.
01:54The End of the
01:55The End of the
02:27It's a one-hour drive up the Nile from Cairo to reach the southern limits of the necropolis
02:32of the pharaohs, a site that still today withholds a great many mysteries, the Dashur Plateau.
02:43This is where the Bent Pyramid takes center stage.
02:48For centuries, people have wondered about its enigmatic shape.
02:52But what exactly were the ancient Egyptians' intentions here?
02:57It's really hard to understand.
02:59It's very different from the others.
03:01Why was it made this way?
03:03Was it deliberate?
03:04Was it an accident?
03:06Does it have some ideological, religious meaning?
03:09So, the Bent Pyramid, in a way, is one of the most mysterious of all of Egypt's buildings.
03:17Frank Monnier is an engineer who specializes in ancient Egypt, one of the top experts regarding
03:23pyramid construction.
03:25He has long been fascinated by the puzzle of the Bent Pyramid.
03:30Having been closed to the public for decades, the structure has only been accessible for
03:34the last few years.
03:35This is Frank's first opportunity to go inside.
03:40I feel very emotional about finally being able to go into the heart of this pyramid.
03:43There's a lot of talk about the mystery of the Bent Pyramid, and there are many problems
03:48still unsolved.
03:49But now, I'm finally going to be able to judge for myself what's inside.
03:54But even just getting inside is far from simple.
03:57You first have to climb 12 meters up the north face of the pyramid to reach the entrance, the
04:03height of a four-story building.
04:08From there, you plunge into the long descent, down a sloping 80-meter corridor barely a meter
04:14high, which is particularly tricky to negotiate.
04:18Today, stairs help visitors descend this very steep corridor.
04:23But there was no such aid in the time of the pharaohs.
04:26General people, the great unwashed, like us tourists who go today, were not meant to
04:32go inside these things.
04:33So the faces of those sloping corridors would be smooth.
04:37So it would be really difficult without a rope, or with some kind of handholds, to get
04:43inside.
04:45At the bottom of the slope, you finally get to behold the pyramid's first chamber, known
04:50as the antechamber.
04:57What a marvel.
05:01A cathedral inside a pyramid.
05:06It's incredible that it goes so high.
05:09And it's in really excellent condition.
05:14Superb!
05:14Almost 4,600 years after it was built, the state of preservation of this chamber is quite
05:20spectacular.
05:21The walls are smooth, and the care taken over the joints between the blocks of stone is still
05:26clear to see.
05:27But the most impressive aspect of the chamber is its height.
05:31It's amazing to see a chamber go up so high.
05:33It's the highest chamber found in any pyramid.
05:37The height is over 17 meters.
05:40It's extraordinary.
05:42But how did the Egyptians manage to create such a grandiose space?
05:47What techniques did they use to reach such a height?
05:59The internal structure of the pyramid has intrigued Egyptologists for a very long time, and for
06:04a simple reason.
06:05It holds the key to the puzzle of its unusual appearance.
06:11The interior structure of the bent pyramid is as interesting as the exterior, because
06:16it actually has two entrances or exits, depending on how you look at it.
06:21And so there are two different ways of circulating.
06:25It was the first time they'd built successive chambers.
06:29The bent pyramid, when you look at later pyramids, does seem like a bit of an experiment.
06:35The interior and its complexity raises lots of questions.
06:41The complex arrangement of the various apartments is very unusual.
06:45Clearly, there must have been changes to the plan as it was being built.
06:52But what were the reasons for this?
06:55Why did the builders have to revise their plans?
06:57What challenges did they have to overcome?
07:00There are so many questions still awaiting an answer.
07:09Engineer and Egyptologist Frank Meunier knows the plans of the pyramid by heart.
07:14Engineer and Egypt.
07:20On this sheet of tracing paper, I've drawn the funeral apartments of the Bent Pyramid.
07:25Everything is represented here in one cross-section.
07:28The lower apartments accessed from the north entrance and the upper apartments accessed from
07:33the west entrance.
07:34It would be really interesting to use the laser to scan the antechamber of the lower apartments.
07:41To get a clear insight, he's decided to undertake a new and unprecedented mission inside the
07:47pyramid.
07:53To this end, he's called on Alban Brice Pimpot, an archaeologist who specializes in digital
07:59imaging.
08:00He's going to use a lidar, a laser scanner, which records hundreds of thousands of measurements
08:05per second in 360 degrees.
08:13This high-performance equipment can make measurements of distance and volume of unparalleled precision.
08:25It's the first time this cutting-edge technology is being used on the bent pyramid.
08:33The entire interior of the structure will be scanned, even spaces never previously visited,
08:39with a totally unprecedented level of detail.
08:44My mission today is to scan the interior spaces of the bent pyramid, to try and document as
08:51much as possible, and collate all this detailed geometric information.
08:59The bent pyramid structure has two different inclinations, which you can probably get a
09:04sense of from the interior spaces, so it'll be interesting to document it with the scanner.
09:09This digital scanner is so miniaturized that it can be introduced into every part of the pyramid,
09:15but it could still be tricky in some of the tightest spots.
09:20In such narrow confines, it's always a bit delicate to do the digitization, because the
09:24changing angles can cause problems.
09:26They're tricky spaces to scan.
09:34After scanning the long sloping corridor, Albon-Bris Pampo reaches the antechamber.
09:41In this large open space, he can deploy his scanner more easily.
09:47The results should shed light on how the Egyptians were able to create such a vast space in such
09:53an ancient era 4,600 years ago.
10:00The man behind this off-the-scale project was one of history's greatest builders, the pharaoh
10:06Sneferu.
10:16While his name isn't that well known today, Sneferu was a true legend in the Egypt of the pharaohs.
10:24It was Sneferu who built the first great pyramids.
10:27He was an extremely well-known king in ancient Egypt, the very example of a pharaoh.
10:33There wasn't Khufu, it was Sneferu.
10:37In folk tales, he is called a beneficent king, so the image of him presented in later literature
10:45seems to be of a very sort of jolly, very demotic kind of king.
10:51Sneferu founded the fourth dynasty, the most famous of ancient Egypt's dynasties.
10:56He was the father of Khufu, who lived in around 2600 BCE.
11:01This was the very heyday of the ancient empire, the golden era when the giant pyramids were
11:06built.
11:08Sneferu's reign was a long one, lasting quite probably 40 years, during which time the country
11:14underwent profound changes.
11:16Egypt was at the height of its power.
11:21Sneferu opened up a new era in Egyptian history.
11:23The world really did change under Sneferu.
11:27To have the economic resources and the resources in terms of personnel to carry this out, Egypt
11:34must have been in very good shape under Sneferu's reign.
11:45Sneferu's reign was a time of power and prosperity.
11:49He was able to expand trade networks, develop the economy, improve administration, and all
11:57of those activities enabled him to have the resources and the bureaucracy to create his massive pyramids.
12:11After several weeks of digital analysis, the scan results are finally ready.
12:19They give a very clear overview of the first chamber.
12:24Egyptologist Vassil Dobrev sees the images for the first time.
12:28What we often had before were cross sections from which you couldn't get an idea of the three dimensions.
12:35Now we can move around in every direction and try to understand things.
12:42Studying this is a lot easier.
12:46The first observation is of the incredible technical nature of the chamber's architecture.
12:52The first thing I notice right away is that this is a perfectly corbelled construction.
12:57Each block is placed on the one below with a 10 centimeter shift inwards so that it gradually closes.
13:04And this goes up for 17 meters.
13:07This technique of stacking the blocks like an upside down staircase did not happen by chance.
13:13On the contrary, it shows the great ingenuity of Sneferu's architects.
13:17For the first time, they wanted to build actually inside a pyramid.
13:21So to protect the funeral apartments, they had to innovate and invent a structure that would dissipate the forces.
13:30Corbelling is a system of roofing a room by gradually stepping in each course of masonry as you go up
13:40a slight distance.
13:41So eventually the whole thing becomes almost like a triangle in steps going up to the roof.
13:48It seems to be an architectural innovation by engineers working for Sneferu.
13:52At the ceiling, the quality of the builder's work is quite remarkable.
13:57The Corbelling we can see here in this antechamber is in an exceptional state of preservation.
14:03Just think, it's over 4,500 years old.
14:06There are about 104 meters of masonry all stacked up.
14:09Think about that, 104 meters of masonry.
14:11That means thousands of tons weighing down on this chamber and the Corbelling vault is still perfectly stable.
14:18While the antechamber would appear to be perfect, a closer look reveals that something isn't quite right.
14:27Sneferu's builders apparently encountered some problems during the construction.
14:32On this wall here, you can see some pretty serious cracks.
14:35It really looks like the block must have moved.
14:39The whole thing holds together.
14:41But there were small shifts in the structure.
14:44And you can see that this crack here was patched up and renovated quite recently.
14:51The restoration work, carried out so that the pyramid could be made accessible to the public,
14:56has to some extent concealed this extremely ancient fissure with cement.
15:03But the analysis done with the LIDAR scan provides a clearer view.
15:08The technology gives a negative image, which reveals details invisible to the naked eye.
15:14The scan clearly shows that there were some small movements, small cracks,
15:20which ended up creating gashes in the walls of the antechamber.
15:25Right here you can see a bit of a bulge, a very clear crack.
15:32As if some external pressure had pushed a section of the wall out of place.
15:37How do we explain this gash several meters high, right at the heart of the pyramid?
15:43Could these flaws inside the pyramid have been caused by the very way the building was designed?
15:50The answer could come from the context of its construction.
15:58It's hard to imagine, but this pyramid was in fact the second one that the pharaoh envisioned.
16:06Snefru started his pyramid building journey in Medum.
16:10And it initially began as a step pyramid.
16:15The Medum pyramid, 45 kilometers further south, was the first pyramid that Snefru had built.
16:21It looks particularly strange to us today.
16:27But it was originally planned as a step pyramid, like all those built up until that time in Egypt.
16:34Right up until Khufu's father suddenly decided to change things.
16:40Mark Lenner is one of the world's most famous authorities on pyramids.
16:45He's been studying them for 40 years and remains fascinated by the bent pyramid and the story of Snefru.
16:51He builds a giant step pyramid at Medum.
16:55This is important for understanding this monument.
16:58He starts it with six steps, then he enlarges it to seven steps, and then he stops.
17:05In about the 15th year of his reign, he came to Dashur to start the bent pyramid.
17:12But why move that immense workforce to start again from scratch on such a colossal building project?
17:18What drove the pharaoh to make this radical decision?
17:24I think Snefru sincerely wanted to build a true pyramid with straight sides.
17:29He did not want a step pyramid that was no longer satisfactory for his burial place.
17:35So Snefru looked for a new place to start his brand new innovations.
17:42A true architectural revolution. The first true pyramid in human history, a perfect triangular shape.
17:51It seems that religious considerations may have been behind this idea.
17:56The switch seems to be from some kind of stairway to heaven to the idea of the king being buried
18:04under a petrified version of the sun's rays.
18:08This was the development of sun worship.
18:10Pyramid-shaped monuments were part of this equating of the monarchy with the sun.
18:15For him, it was merging himself and his burial place with the rays of the sun.
18:25Snefru's perfect pyramid, with its smooth sides, would reflect the sun and allow the pharaoh to ascend to heaven after
18:32his death,
18:33by which means he would be united with Ra, the sun god.
18:37He demanded of his architects a technical feat totally unheard of at that time.
18:45Only, as anyone can see, his plan did not work.
18:50At 47 meters from the ground, the inclination suddenly changes.
18:55So what happened?
19:00Looking for an answer, Frank Meunier retraces his steps, making his way back up the long slope.
19:08And it's now that he makes a surprising discovery.
19:11Twelve meters from the entrance, strange empty spaces are apparent on either side.
19:17These are particularly clear on the LIDAR scan.
19:22It's quite strange, because here we are, twelve meters from the entrance to the pyramid, and what do we find
19:27here?
19:29Features characteristic of the entrance to a pyramid.
19:31An outer wall, and these famous notches, which here have been filled in, but which would usually be found at
19:39the entrance,
19:40are here, and its counterpart here.
19:42These would have held a beam that would have helped workers get up and down.
19:49These notches were filled in during recent renovations, but they're usually found at the entrance to a pyramid.
19:57What is the explanation for their being here?
20:00Why are the features of an entrance found a good distance down the corridor?
20:04This is a very serious clue, allowing us to surmise that what was here at this place was the original
20:11entrance to the pyramid, as it was first built.
20:15The pyramid, as it was first built. In other words, another structure is hiding inside the current pyramid.
20:23It's a fascinating discovery. To find out more, Frank Monnier takes measurements of the wall.
20:29But it suffered the ravages of time, and isn't perfectly straight.
20:34I'm using an inclinometer, which lets me measure the angle of inclination of this wall, this side.
20:42So, if I position the inclinometer, it tells me that the wall is at an angle here of 62.74
20:50degrees.
20:51If we move it a bit, here we get about 62.
20:55What do we have here? About 58, 59.
20:57You see, it's not consistent, but as an average, it's not far off 60 degrees.
21:02So this must be the wall of the pyramid as it was first built.
21:05A pyramid whose sides were intended to have a slope of about 60 degrees.
21:12A very different inclination from that of the sides of the pyramid we see today.
21:18Thanks to Frank Monnier's measurements, the pyramid hidden on the inside is now revealed to us.
21:23But what did it look like? Was it different from the one before our eyes today?
21:29According to the Egyptologists' calculations, it had a base that measured 157 meters along each side,
21:36making it the biggest ever built up until that time in Egypt.
21:40With its extremely steep sides, at 60 degrees, the pyramid's peak would have been at the phenomenal height of 136
21:48meters,
21:48the same as a 40-store tower block, and twice as high as Djoser's pyramid, which was up until then
21:54the highest in the world.
21:59The pharaoh, to emphasize his power to his people whilst he was alive, was building a very big structure.
22:06He knew in the future it would be very difficult to remove that monument, so he would hopefully, through that,
22:13live forever.
22:13Sneferus said, I want a true pyramid, like the rays of sun.
22:18But nobody knew, should it be 43 degrees, should it be 50, should it be 60?
22:23He chose 60, a very steep slope.
22:25But they didn't know what a true pyramid looked like, how steep it should be.
22:29All the pyramids before, they were step pyramids, they weren't true pyramids.
22:37But then, when the entire interior of the pyramid was finished, the plans were suddenly changed, for a reason that
22:43still remains a mystery.
22:48Maybe, at some point, they realized they had to build a pyramid with 60-degree slopes,
22:53and to extend that to the summit, using ramps of whatever kind it might be, would be extremely difficult and
22:58would require a huge amount of energy.
23:00I think they were having problems in the 60-degree pyramid, and that's why they lessened the slope, that's why
23:06they put a mantle about it.
23:08And everything suggests to me a change in plan as you build, typical for ancient Egyptian builders.
23:17So the Faro's architects decided to modify their plans.
23:22A thick covering of masonry was now added to the four sides of the construction to consolidate it.
23:28The base increased in volume by 20%, with each side now over 189 meters long.
23:35This also considerably reduced the angle of the slope to 54 degrees.
23:42It must be because of this decision that the pyramid has the unusual shape we see today.
23:49Because this enlarging would have consequences that were unexpected and catastrophic.
23:56The Egyptians hadn't anticipated the different ways in which the outer covering and the inner core would behave.
24:03The higher up the covering was from its base, the more it settled,
24:07whereas the inner core remained constant with its characteristics unchanging.
24:12There were major fissures started appearing in the structure, and also blocks have fallen from above, all of which suggests
24:21that everything was not well.
24:27The immense quantity of masonry added by the Egyptians weighed far too heavily on the original pyramid.
24:33As more weight was added, the compression increased.
24:38The evidence of these problems is clear on the inside of the pyramid.
24:44In the sloping descent from the north entrance, there are impressive traces, particularly where the entrance to the original pyramid
24:51was.
24:52Wow, here we have entire slabs of rock, of stone, which have come detached and are ready to fall on
25:00us.
25:00It's pretty scary.
25:02Here we have a big crack, which gives you a view inside the guts of the construction with thin slabs
25:09of rock that have come detached from the blocks,
25:12from these blocks here and the next blocks, quite simply because the outer covering has slipped and slid, breaking off
25:20large lumps of rock.
25:24Sliding down the core of the pyramid, the added masonry caused major cracks throughout the edifice.
25:34We see them as well on the outer layer.
25:38You can see very substantial fissures cutting right through different courses of limestone.
25:45The biggest crack is right here.
25:51It's cracking and snapping and they're trying to chisel it out and patch it as they go.
25:59Seeing all these fissures appearing, Sneferu's architects realized their mistake.
26:05The very structure of their perfect pyramid was in danger.
26:13They had come up with a solution and quickly.
26:16They had to adapt before the building deteriorated further.
26:23And the builders had an idea that was as ingenious as it was simple to try to save their pyramid.
26:30The change from a proper straight-sided pyramid to the bent form is probably to do with an attempt to
26:37reduce the sheer amount of weight which was being placed on the site.
26:41They decided they needed to reduce the weight, reduce the slope, and so they went, oops, and reduced it to
26:4943 degrees.
26:51The Egyptians realized that by radically lessening the slope of the sides to an angle of 43 degrees, the building
26:58process would be a lot easier.
27:01Above all, they understood that this would reduce the mass weighing down on the foundations, thereby giving the edifice a
27:08firmer foothold.
27:10This was how Sneferu's pyramid, initially intended to have perfect triangular sides, ended up with its unusual shape.
27:18Proof of the ingenuity and amazing adaptability of the builders of the pyramids.
27:24They were adapting, they're working with things, they're meeting challenges, what we would call research and development.
27:31They're responding to challenges and they're working everything out.
27:36Once finished, the pyramid reached a dizzying height of 104 meters, which is almost 10 meters higher than London's Big
27:44Ben.
27:46At the time, it was the tallest construction in the world.
27:50We've calculated that Sneferu's pyramid has around 1.3 million cubic meters of stone.
27:57That's about 3.3 million tons.
28:01It's quite something. No one had ever built a pyramid of such gigantic dimensions.
28:07Despite this feat, Khufu's father was not satisfied with the result.
28:13He decided that he wanted a straight-sided pyramid and he was going to get it.
28:24So, the mighty pharaoh quite simply had a third pyramid made, the Red Pyramid, barely two kilometers from the Bent
28:31Pyramid.
28:35This time, the result was perfect.
28:40There, Sneferu succeeded in building, for the first time, a true straight-angled pyramid.
28:48The true pyramid that he had long wanted to achieve.
28:52Finally, there was a true pyramid representing the rays of the sun.
28:56When you look at it, it seems to be attempting to address all the lessons from the building of the
29:05Bent Pyramid.
29:08Sneferu's architects had finally succeeded and pulled off the incredible achievement of building the first straight-sided pyramid in human
29:16history.
29:20They'd learned from their mistakes making the Bent Pyramid.
29:26Taking no risks, right from the start, they decided on an angle of 43 degrees, the inclination at which they'd
29:32topped off the Bent Pyramid, and a guarantee of far greater stability.
29:48But some Egyptologists are not convinced by the theory of the design accident in the building of the Bent Pyramid.
29:56Among them is the archaeologist Vassil Dobrev, one of the top authorities on the ancient empire.
30:02He believes the edifice was intended, right from the start, to have this peculiar shape.
30:08The Egyptians wanted to imitate the primal hill in which Egypt was supposed to have been created.
30:13They believed that in the beginning, there was the primordial ocean.
30:17And out of this primordial ocean, there emerged the first hill, which they called Ben Ben, because it had two
30:23shapes, like this.
30:24Ben, Ben.
30:25I think the Egyptians wanted to express this bursting out of the sea with this shape.
30:30So the shape was totally intentional.
30:38Maybe this was an experiment, actually, to get to this obelisk shape that was intended all along.
30:46Ben Ben was in fact a stone which was supposed to be the place where the sun settled at the
30:51moment of the creation of the world.
30:52So it was a powerful symbol of the sun, which inspired the shape of the Egyptian pyramids.
30:58In this case, the Red Pyramid and the Bent Pyramid would have been built at the same time.
31:03The two intended to work together as some sort of powerful resurrection device.
31:08There is a sense in which the Red Pyramid and the Bent Pyramid are counterparts.
31:13I think they were meant to work as a couple.
31:16One to raise the resurrected king up into the sky, and the other to bring him down, by means of
31:22the sun's rays.
31:23And the proof that these two were meant to work together is that they're both the same height.
31:29So they form a monument to the sun, which let the pharaoh come back down to earth, and so on,
31:34in an eternal circle.
31:49Whether they were built simultaneously or consecutively, the interior of the Red Pyramid is very similar to that of the
31:56Bent Pyramid.
31:56The Bent Pyramid and the North Pyramid have similarities in their internal structure.
32:01They both have beautiful corbelled chambers.
32:04The chambers inside the North Pyramid are a little bit more beautiful.
32:08They are probably the most magnificent chambers ever produced in a pyramid.
32:13The final expression, I suppose, of the corbelled roofing.
32:18Inside the Red Pyramid, there's a succession of three magnificent corbelled chambers in perfect harmony,
32:24as though a carefully thought out design plan was followed to the letter.
32:29There's no evidence of any problems, hesitation, or making it up as they went along.
32:37Quite different, then, from the interior of the Bent Pyramid, where the LiDAR scan revealed many flaws in the construction
32:44process.
32:48Back inside the Bent Pyramid, there's another mysterious architectural element, a sort of chimney,
32:54which we've decided to scan digitally in an attempt to discover its secret.
32:58This vertical shaft is a bit of a problem, because we don't know where it goes.
33:02It is not clear, because there are no texts or no obvious structural reasons why or what that was intended
33:12for.
33:12So people are puzzled by it today.
33:16It is the first time it's been possible to film and scan this shaft from the inside.
33:23At a height of 15 meters, two huge blocks of limestone come together to block the way.
33:29It's a dead end, an unexplained cul-de-sac.
33:32What could it be for?
33:34The LiDAR scan could shed some light, but it is a tricky operation for Alban Brice Pimpou.
33:40He's going to need a very long extension in an extremely tight space inhabited by bats.
33:49I'm about halfway up the chimney, about 15 meters to the top, and my extension has got me to about
33:586 meters.
34:01That's not too bad, I think.
34:04We'll see what imaging we get on the computer.
34:07I'm knowing the bats. There are a lot of them up there.
34:12Every second, the device takes over 400,000 measurements.
34:18You can hear the scanner getting noisier and faster as the processor is warming up.
34:24It's having to calculate lots of different points in a pretty narrow space, so it's struggling to find its bearings.
34:31I'll bring it down. That should be enough.
34:36Thanks to the scan, we get, for the first time, a complete view of the chimney, with a level of
34:42precision never before achieved in this spot.
34:46When you visit the place, you wonder what's up there above your head.
34:51It's not clear at all, but here the laser scan shows us every little detail of the chimney.
34:58The results of the LiDAR scan produce some precious clues.
35:02We can clearly see the compartments for the two closing blocks, the two obstruction systems,
35:07the two blocks waiting to be tipped over to seal off the passage, but which are still in their untipped
35:12positions.
35:14In pyramids, blocks like these were intended to be tipped over to seal off the access to funeral chambers.
35:21Their presence shows that this chimney should have led somewhere.
35:25But strangely, the blocks remain in their upright positions.
35:31These blocks have remained in their untipped positions, meaning they were never closed.
35:35Which makes you think that the plan had been to build a funeral chamber at the top of the chimney,
35:39but that they gave up on the idea.
35:43There was clearly a major change of plan.
35:49To try to clear up this mystery, the Egyptologists have had the idea of comparing this layout to those of
35:56other pyramids.
35:58In the end, it seems like the answer might lie with Snefrou himself and his first pyramid.
36:06Back to Meidoum, 45 kilometers further south.
36:10At Meidoum, there's a chimney, which leads to a small funeral chamber, which is good reason to believe that we
36:18have the same thing at the Bent Pyramid.
36:20An anti-chamber, a chimney.
36:22But in the Bent Pyramid, the funeral chamber was never built.
36:28It would seem, then, that the chimney in the Bent Pyramid was supposed to lead to a funeral chamber.
36:35But Snefrou's builders gave up on that original plan.
36:39Maybe because of the technical difficulties involved.
36:45It's really difficult to lift things up a vertical shaft, and it's not very wide.
36:50Let's not forget that this was the first grey pyramid.
36:53They were experimenting and adapting.
36:56Conducting the funeral up a 15-meter-high chimney, getting the pharaoh's body up there with the sarcophagus and all
37:01the funeral furniture,
37:02would have required some acrobatic maneuvering, so it probably ended up not a very popular option.
37:08As with any architectural project that lasts decades, there are necessarily times when plans get modified, when people change their
37:17minds.
37:25So the Egyptians gave up on this shaft, and had a radical change of plan.
37:32They decided on a second and totally independent orientation.
37:37While the entrances to Egypt's pyramids were always on the northern side,
37:41this new descending slope was brought in from the west.
37:45Yet another mysterious choice.
37:50The western entrance of the Bent Pyramid is very mysterious.
37:54There are no other old kingdom pyramids with such an entrance.
37:57The best solution would seem to be that it was a substitute burial complex intended for the burial of the
38:05king.
38:06Maybe this has something to do with ideology.
38:08The west was also where the dead lived, so maybe that was also another pathway for the king to enjoy
38:16another afterlife by going through the west the same way that most people went to the west at death.
38:30This corridor symbolically could have been where Osiris would meet the newly resurrected king Sneferu, in the western side, which
38:38led to Osiris' world, because that's where the sun sets and the direction in which the dead go.
38:48Osiris was the god supreme of the underworld.
38:52All the dead of ancient Egypt would have to pass by him.
39:00The entrance to this second corridor is almost 33 meters above the ground, as high as an 11-story building,
39:07making it the highest entrance of all of Egypt's pyramids.
39:12There's two possible reasons for this. One is that it could have helped deter thieves from breaking in.
39:18But the other reason is that it actually elevated the king closer to the heavens, where his spirit wanted to
39:25fly out.
39:26The opening was invisible. It was perfectly hidden by a covering block.
39:32At the end of this second sloping corridor, almost 70 meters in length, a horizontal corridor 20 meters long led
39:40to the funeral chamber.
39:49So here we are in the Holy of Holies, the funeral chamber.
39:53The amazing thing? When you get into this chamber, it's the state that it's in. You feel like you're in
39:59a natural cave.
40:01The walls have suffered some serious deterioration.
40:07This was the chamber intended to be the final resting place of the pharaoh's body.
40:12But the deterioration of the vault is quite startling.
40:16The corbelling of the ceiling is barely recognizable. It feels like being in an underground cave.
40:23We saw those problems in the burial chamber. There's evidence of serious cracking in the walls of that chamber.
40:32What happened for it to end up in such a pitiful state?
40:36Did Sneferu's architects make a mistake here?
40:40Seeing the state of the chamber, along with the results of the LIDAR scan,
40:44Frank Monnier makes an initial observation.
40:47The damage isn't only of a structural nature, it was caused by a reworking done by the Egyptians on the
40:53corbelling and the walls.
40:58After the chamber had been completed, with its corbelled vault at a height of 14 meters,
41:03the Egyptians suddenly decided to raise the floor of the chamber by filling it with masonry.
41:09And they did so twice.
41:14It's a total mystery. We have absolutely no idea why they decided to do that.
41:19It's unique. We don't see a modification like this in any other pyramid.
41:25But the modification is no longer present.
41:29There was all this masonry, which came up to here, but it was removed by explorers and archaeologists in the
41:3520th century because they hoped to find secret passages or a sarcophagus that hadn't been plundered.
41:43In the last century, the archaeologists working on the pyramid removed practically all the stones in the hope of finding
41:50a secret passage or, even better, Sneferu's sarcophagus.
41:57But they were soon disappointed. There was no trace of the pharaoh and no secret passages, just a gaping hole.
42:06But their efforts did clear the space, thereby revealing the traces of the modifications done by the Egyptians.
42:12You can clearly see on the sides some slabs of the first load of masonry that was removed by the
42:18archaeologists.
42:19And you can clearly see, just above the cedar beams, that there still remains some elements of the floor of
42:25that first load.
42:26They're sticking out a bit. That was the first load of masonry that was removed.
42:31And the archaeologists' labors did result in one incredible discovery.
42:38They revealed this ancient timber work.
42:41All the beams you see there are over 4,600 years old. They're original.
42:46You can touch the wood. It's still firm. It hasn't suffered the ravages of time at all.
42:52It's absolutely wonderful. It's a step back in time.
42:55If you buried wood in Europe, it wouldn't generally last more than a few years.
43:02But in ancient Egypt, and in Egypt generally, the climate is so dry, it's so arid, there's a lack of
43:08humidity,
43:08and so that wood, which is, you know, 4,500 years old, has been preserved.
43:14It's thought that this timber work provided a temporary stay, a support for the walls while the chamber was being
43:20built.
43:24The wood is Lebanese cedar, which had to be brought here from the coast of the Middle East.
43:30You couldn't find any timber suitable for construction purposes in Egypt.
43:35Palm trees are very fibrous and wear out quickly, so they never used them.
43:39They had to go looking for wood outside Egypt.
43:42The Egyptians were trading with Lebanon, and the cedar would have to have been cut from the mountains,
43:48brought down to the sea, and then transported to Egypt.
43:52And it's extraordinary that this happened.
43:55In terms of construction, this kind of wood would be much more solid and strong.
44:04But these wooden structures were in no way responsible for the degradation of the state of the chamber.
44:11Having raised the floor, Sneferu's builders decided to rework the vault to obtain smooth walls,
44:17no doubt to achieve an effect more befitting a funeral chamber.
44:25But architecturally, it was a serious mistake.
44:28You can clearly see the straight side here. The corbelling has been worked away.
44:34And they did this up to a certain height.
44:36But what was the result of this reworking?
44:38An unequal distribution of the forces.
44:41It undid the whole principle behind the construction of the vault.
44:46The vault was no longer able to bear its load, and the ceiling started to deteriorate.
44:52The blocks were jutting out too far from the walls and ended up giving way, cracking and even falling.
44:58Look up there. That's pretty impressive.
45:00This is a straight-sided part of the wall.
45:03They must have left some blocks in too unstable a position, and they caved in.
45:07I'd say there's a good chance the stone started to crack and fall even while the pyramid was still being
45:12built.
45:13To check the state of the chamber in greater detail, Frank asked Albonbris to scan the entire room.
45:20But the task isn't that easy.
45:22The conditions inside a pyramid are always a bit special.
45:25It's not always easy to get around.
45:27The atmosphere is a bit warm, and it quickly gets oppressive.
45:30So you can't stay long.
45:32You have to be very efficient and get the data quickly.
45:38It is purely thanks to this miniature mobile scanner that the operation is possible at all.
45:44The data it gives us will be unique and unprecedented.
45:49After he's finished, Albonbris can immediately check on his phone that the scan has been successful.
45:56This is a quick preview to check that it worked.
46:00It looks fine to me, so now I'm impatient to see what we get on the computer,
46:03because there'll be a lot more detail and some color.
46:08It takes Albonbris a few days to create a 3D model of the chamber.
46:13The details are stunning.
46:17Discovering these new images of the chamber, especially with the negative view,
46:22Frank Meunier makes a somewhat worrying observation.
46:25You can see it very clearly.
46:27The scan has revealed some joints that are completely open.
46:30What you're seeing is empty space.
46:33And this empty space sometimes continues behind the blocks of the corbelling.
46:37So that means either an open joint or fissure with part of a block ready to fall.
46:41Here we see a piece of block which, sooner or later, is going to fall.
46:46The LiDAR scanner has shown that the structure may not be totally stable.
46:51Here we have plenty of elements whose stability is a bit precarious.
46:57It's safe to say that this fissuring will continue for centuries
47:01if we don't take measures to preserve and consolidate this chamber.
47:08This, then, is how this superb corbelled vault, intended to crown the funeral chamber,
47:13gradually crumbled away to end up looking so dilapidated today.
47:24No doubt because of the structural problems that kept getting worse inside the pyramid,
47:29the Egyptians finally decided to seal off the entire western passage,
47:33the second they had built.
47:39The structural problems caused them to close the western passage,
47:45plug it completely with limestone blocks.
47:49A ramp would have had to be built for this,
47:52up which they could haul the huge blocks of limestone that would be used to plug up the passage.
47:57You have to try to imagine the enormous difficulty of plugging up this sloping passage that's about 67 meters long.
48:03They must have dropped in blocks weighing several tons,
48:06which would have hurtled down at great speed one after the other,
48:10to completely seal off the corridor.
48:14But the builders had to find some way of making access to the funeral chamber still possible.
48:21They decided, therefore, to quite simply hollow out a tunnel through the edifice's masonry.
48:26It was done during the construction of the pyramid to allow workmen to easily go between the two complexes of
48:34chambers.
48:35Ironically, the northern entrance became the entrance for the higher western chamber,
48:40all because of these structural problems.
48:43Every small step you can see they're responding to challenges, to structural problems.
48:50We asked Frank to take us through this tunnel.
48:58About 20 meters long and roughly hewn through the limestone blocks,
49:02this sinuous corridor is particularly narrow and uncomfortable.
49:13You can imagine the problems the Egyptians had to face digging this tunnel.
49:19Just squatting to get through it now is quite an ordeal.
49:22So just imagine the Egyptian workers who had to dig it and carry heavy objects through it.
49:28That's something.
49:31A LIDAR scan could reveal how these workers managed to hollow out this corridor blind right through the heart of
49:38the limestone.
49:41It takes Albonbris an hour to scan the entirety of the corridor, but the result is spectacular.
49:49The details of the masonry, the measurements calculated to the millimetre, the volumes, everything appears in digital form.
49:58And before our very eyes, this 3D model reveals the amazing engineering technique perfected over four and a half thousand
50:05years ago.
50:06At first sight, you'd think they just dug through blind, that the workers at this end started their tunnel,
50:13and those here started their tunnel, both hoping they'd meet.
50:17But it wasn't left to chance at all.
50:19To make sure that the two teams would meet, both teams made a bend, a sort of deviation.
50:25If they both went off this way, they were bound to meet sooner or later.
50:32The precise route of this linking tunnel proves that it could only have been created by the builders themselves,
50:38and not thieves long after the pyramid was finished.
50:42The fact that it goes directly between the two chambers does suggest people knew exactly where they were going.
50:48It does show a level of expertise.
50:50It shows that they were able to dig a tunnel through existing masonry,
50:55but also that they were able to direct the inclination and the direction of the tunnel.
51:00And that could have only been possible if there were plans for them to consult.
51:06So it was via this narrow passage that Snefu's funeral cortege would have had to pass,
51:11to carry the pharaoh's mummy to his sepulchre, the funeral chamber.
51:22But one mystery remains regarding this tunnel dug for the transportation of the mummy of Khufu's father.
51:29And it's the big question that's still bothering Egyptologists.
51:33Did the dead pharaoh ever come this way?
51:36In which of his three pyramids was he finally laid to rest?
51:40So far, no sarcophagus has ever been found,
51:44neither in the pyramid at Maedum, nor in the Bent Pyramid, nor in the Red Pyramid.
51:50But the clues suggest that the pharaoh would have chosen the perfect Red Pyramid as his gateway to the afterlife.
51:56I think it's compelling that Snefu was buried in the North Pyramid,
52:00in the true pyramid that he had long wanted to achieve.
52:05There he could be buried in the reflected light of the sun god itself.
52:10It was successful in creating the vision he wanted.
52:13It had all the things he wanted in the pyramid design itself.
52:18So, most probably, that's where he was buried.
52:21It was the last pyramid built during his reign,
52:23and it offered all the guarantees of security and stability that he could expect from his resting place for eternity.
52:32Yet, troublesome details still muddy the waters.
52:36What if Snefu's body is actually in the most mysterious pyramid of all, the Bent Pyramid?
52:42This is where the worshipping took place.
52:44It was to this pyramid that the priests came.
52:47It was where offerings were made for thousands of years.
52:50So, the Egyptians themselves definitely thought that this is where the king was buried.
52:55And then he would go to heaven.
52:59Whatever the case, the name of Sneferu, while perhaps not known well to the general public,
53:04has gone down in history as that of the greatest builder of ancient Egypt.
53:09Sneferu builds more pyramids in terms of cubic meter age than any pharaoh of Egypt.
53:17So, on those terms, he is the greatest builder in stone, at least, in ancient Egypt, if not in the
53:24whole ancient world.
53:27The three pyramids together comprise about 8.3 million tons of stone, a weight equivalent to 820 Eiffel Towers.
53:37The figure is hard to imagine, the quantities of material and the amount of labor needed being off the scale.
53:44And all this, 2,600 years BCE.
53:49Despite the problems encountered in its construction, the Bent Pyramid has survived the centuries to stand before us today like
53:56no other building in Egypt and perhaps in the world.
54:01And the lessons learnt by Sneferu's architects of the Bent Pyramid made the construction possible of those absolute masterpieces of
54:08antiquity,
54:10possibly the world's famous buildings, the Pyramids of Giza.
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