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00:03the Acropolis a mighty hilltop wonder over 2,000 years old the sheer scale of
00:12these temples is almost unimaginable how did the ancient Greeks construct these
00:19extraordinary buildings it's really fascinating and it's a huge puzzle what
00:26long-lost rituals were they used for and how have they survived while other
00:30ancient buildings have crumbled away the only way to solve these mysteries is to
00:39blow this temple complex apart
00:44exploring its structure stone by stone will help us unearth the astonishing
00:48engineering secrets hidden inside this ancient wonder
01:12perched high on a massive rock overlooking the city of Athens stands a landmark of
01:17Western civilization the Acropolis here 2,400 years ago the Greeks built an
01:29extraordinary complex of temples where they could worship their gods
01:36now as restores dismantle and rebuild it the Acropolis is revealing its hidden secrets
01:45new clues are emerging from the restoration of its two largest buildings
01:50the world-famous Parthenon and the imposing entrance gateway known as the Provo Leia
02:01the Parthenon was the greatest temple of its age
02:12a wonder of the ancient world
02:16from 22,000 tons of precious marble Greek stonemasons assembled a building of exquisite perfection
02:28it's 13,000 individual stones fitted together so precisely the joints were watertight
02:37it's 58 towering columns could withstand earthquakes
02:42it's an extraordinary structure but how exactly did the ancient Greeks constructed
02:56the secret to the Parthenon's perfection begins with its special building material
03:01the secret to the Parthenon's perfection begins with its special building material marble
03:05its largest blocks are massive weighing in at 10 tons each but no marble existed in Athens
03:16so how did the ancient Greeks find and transport these enormous pieces of marble to this dizzying hilltop site
03:29the answer lies at Pentelicon over 10 miles from the city
03:36historian Edith Hall has come here to piece together this ancient mystery
03:44this is the very birthplace of the Parthenon
03:47these great rock faces where they cut down the marble
03:51and took it all the way to Athens to build the Acropolis
03:53and everywhere you look there's just glittering white marble
03:56just stones of every size
03:58I mean look at this one
03:59just pick it up off the floor
04:01you can actually see how incredibly gleaming white it is
04:04there's sparkly bits that you can see once it's polished up and smoothed down and chiseled
04:09it would actually gleam in the sunshine
04:12it's actually incandescent
04:17although Edith is surrounded by marble at the ancient quarry
04:22most of it is in small pieces
04:27in ancient times craftsmen would have struggled to find the enormous blocks needed to build the Parthenon
04:35today workers at this modern quarry on Mount Pentelicon face the same challenge
04:42the blocks from here are considered special
04:46they're highly priced because of their quality, their whiteness
04:52they are from the same seam of marble as the ancient quarry
04:56and are used for the Acropolis restoration
05:01it's exactly the same marble the ancient used to make the constructions
05:05and in Parthenon
05:07it's not exactly the same place as the ancient did
05:10but it's exactly the same marble
05:18even with modern machinery extracting large blocks is difficult
05:24the rock is full of natural fissures
05:27tiny cracks that cause the marble to break
05:33diamond coated wire saws slice through the stone with ease
05:43but once Sotiris extracts the blocks they often break up into smaller pieces
05:51big blocks are needed for Parthenon
05:54one, two, maybe three marble blocks of the appropriate size and strength can be found every year
06:02for the ancient Greeks who only had hand tools
06:05it would have taken years to extract all the large ten-ton stones needed to build the Parthenon
06:13and once they had found their stones they faced an even greater challenge
06:21how did they transport these enormously heavy precious blocks over ten miles
06:25then razed them to the work site at the top of the hill
06:33at the ancient quarry Edith thinks she has found a clue
06:38where I'm standing now is actually the road that was made to transport all those slabs from the quarry
06:45all the way downhill to Athens and to the Acropolis itself
06:50it's downhill all the way
06:51it's quite a steep gradient but it's regular and smooth
06:55and the road's as straight as they could possibly make it
06:58so that the journey was as short as possible
07:00because it was an incredibly hard labour for all of them
07:06workers used mules to pull the stones on carts down from the mountain to the city of Athens
07:14but then came the biggest challenge raising the marble up to the Acropolis
07:23the rock rises nearly 230 feet above the city
07:27there was no way the Greeks could pull the massive blocks directly up this precipice
07:33so how did they haul them to the top
07:38hiding unnoticed by the thousands of tourists who passed this way lies the answer
07:43they built a very smooth stone ramp with quite a slow gradient it's only about 10 degrees
07:50today there are only a few stones left here
07:54but it's clear from their angle that they are part of a massive ramp that once extended from the bottom
08:00of the hill to the top
08:03so how did the Greeks use this ramp?
08:07archaeologists suspect they created the perfect system
08:14at the bottom of the ramp
08:16builders positioned a cart with huge wheels to support the colossal weight of the marble blocks
08:25at the top of the ramp they anchored a massive wooden pulley
08:29a heavy rope ran around it and down to the cart at the bottom
08:34they connected the rope to a second cart at the top
08:36then filled this with rubble from the site to turn it into a counterweight
08:45as the rubble cart rolled downhill
08:47it pulled the marble blocks up the ramp
08:51an ingenious cable car running right up to the Acropolis
08:57it took a huge effort to transport 22,000 tons of stone to the top of this hill
09:05so why did they choose the most difficult place in the whole city
09:09to build these sacred temples and what was their purpose?
09:20the ancient Greeks could have built these sacred temples anywhere in the city
09:27why here?
09:30and what did they use them for?
09:35Acropolis means the high place or the summit of the city
09:37it's where they used to put their treasures
09:39it was originally their seat of government
09:41and it was certainly the place where they were going to worship the gods
09:46on the Acropolis the Athenians felt closer to their gods in the sky
09:57although they worshipped many gods the main temples on this site were dedicated to just one
10:03Athena
10:05Athena was one of the oldest Greek gods
10:07she's the goddess of cities, of civilization
10:09and she's very very often found worship where there's a high rocky citadel
10:14where people tended to form big urban communities
10:17that's why the city is called Athens
10:19it's the city of Athena
10:24Athena was known as the virgin goddess
10:26and so the people named this building from the Greek word for virgin
10:30the Parthenon
10:37historical accounts reveal this was once a shining temple
10:44inside a nearly forty foot tall statue of the goddess Athena
10:49in her hand a human sized figure of Nike
10:52the goddess of victory
10:59around her rises an exquisite building created so the people of Athens could properly worship the goddess they believed would
11:06protect their city
11:08and make it impregnable
11:20they said again
11:22recently archaeologists here have made an amazing discovery
11:26ah
11:27it's something very rare
11:31the remains of a strange structure lie hidden beneath the Parthenon
11:39could it be that the building we see today is not the original
11:49out of sight beneath the floor of the marble Parthenon lies tens of thousands of mysterious limestone blocks
11:59the blocks plunge 22 layers deep on one side
12:04they form a massive wedge shaped foundation that hugs the slope of the Acropolis Hill
12:12investigations reveal that some of these blocks are over 100 years older than the Parthenon that sits on top of
12:18them
12:20a sign that another building stood here long before the monument we see today
12:32so what was this mysterious structure and what happened to it?
12:40archaeologist Elisabeth Siumpara is working to unravel the mystery
12:45how do you see it? tell me
12:47four and one
12:49she and her team are tackling a huge three dimensional jigsaw puzzle
12:56thousands of stones lie scattered within the walls of the Acropolis
13:01not all of these stones are marble
13:05some are limestone
13:07fragments of ancient buildings that existed before the Parthenon
13:13Elisabeth is hunting for pieces of these ancient stones that join together
13:18it's a monumental task
13:20it's a project that is going over 30 years
13:23we have already documented around 23,000 blocks
13:29mainly we are looking to identify where all these stones are coming from
13:35yeah it's a huge puzzle
13:39it's a puzzle with an extraordinary prize
13:45if they can join enough pieces they can figure out what the original buildings look like
13:52we have a roof tile most probable it's something very rare
13:55we give them a number, their ID number
13:58and we document everything under this ID number
14:01their measurements, what they are, from which monument
14:04if we are able to tell
14:06and we bring everything in the computer
14:09and reconstruct how this building was looking like
14:15after years of work, the team has made a major discovery
14:23from the small fragments that the archaeologists have collected
14:27they've pieced together the dimensions of a mysterious building
14:36they've worked out from the decorated blocks that it was a temple with a magnificent entrance at its front
14:44sides 160 feet long
14:46and weighing thousands of tons
14:50it stood proud on a foundation of limestone blocks that still sits deep under the Parthenon we know
14:56right to this very day
15:05amazingly, this ancient temple was another Parthenon built long before the one we see today
15:13but what happened to it?
15:21in her search for answers, Edith thinks she's found a clue in these statues
15:27these are the remains of the sculptures on the temple of Athenia that preceded the Parthenon that we now can
15:35see
15:35and they're really amazing
15:41the statues date from a time just before Athens emerged as the world's first democracy
15:48it's very elemental, it's much more primitive than what we see on the Parthenon that survived
15:55exactly why the temple was destroyed is a mystery
15:59but it's possible that the Greeks considered it old and its mythological sculptures out of fashion with their beliefs
16:07maybe something about the mythology on it wasn't exactly right
16:11what we do know though is it was a very important stepping stone
16:15towards the erection of the great temple that we really identified as the Parthenon
16:23the first Parthenon showed the people of Athens they could construct a stone temple high above the city
16:32but the next generation was determined to build something bigger and better
16:40their achievement constructing the ancient Greek Acropolis we see today was truly extraordinary
16:50from their work on the ancient stones the team restoring the Acropolis is convinced that these were some of the
16:56finest buildings ever constructed
17:01Vasiliki Eleftheriu is the director of the Acropolis restoration
17:05they have to move this block now
17:09the final position is here
17:13today her team is installing an ancient block that makes up the entrance gateway, the Propoleia
17:21the restoration here reveals new evidence that the ancient craftsmen worked with extreme precision
17:30they left markings in the stone that Vasiliki can still use as a guide
17:35we can see the traces the lines of the ancient position and now we put again according to this line
17:50it's a challenge to match the craftsmanship of the ancient builders even with modern tools
17:57all of the technicians today admire the ancient technicians
18:04they knew secrets that we don't know
18:11even after 2,400 years the ancient Greek block still fits into position
18:22to build the Acropolis the Greeks had to repeat this precision over and over again
18:28so how did they do it
18:40ancient masons carved 13,000 perfectly rectangular blocks of marble
18:49they assembled the blocks into 40 foot high walls
18:54outside they stacked over 600 massive marble drums to form 58 towering columns over 3 stories tall
19:05on top they laid stones weighing up to 10 tons
19:10how could the ancient Greeks lift such massive weights and place them with such surgical precision
19:24on the entrance gateway to the Acropolis known as the Propoleia
19:28the restoration team is grappling with the same problem that challenged the ancient Greeks
19:36architect Konstantinos Karanassos and his team must raise an original drum of marble to the top of one of the
19:42columns
19:46the plan is to put the drum at its original position
19:54lifting this 2,400 year old piece of marble requires extreme caution
20:05it's very difficult because we have to be very careful to not make damages
20:10it's very responsible
20:17raising the stone reveals a problem
20:22the straps wrap right underneath the drum
20:26their position makes it impossible to lay the drum directly onto the column
20:32so what did the ancient Greeks do that this modern team is not
20:38one original stone among thousands on the Acropolis holds the key
20:44it looks completely different to a finished column drum
20:48but Edith thinks it solves an engineering mystery
20:52this is very exciting
20:53this is actually a column drum
20:55to make one of the columns of the temples
20:58but in the state it would have arrived at from the quarry
21:01at the quarry it was made into to the circle circular shape
21:05but these big bosses were left on
21:10so what could these knots have been used for
21:18the Greeks had big wooden cranes that could winch ten-ton marble pieces over three stories high
21:26they left the drums uncarved except for the protrusions called bosses
21:33the lifting ropes gripped to the bosses and released with ease
21:38they stacked up eleven drums to build a column
21:45then the masons carved the flutes in perfect alignment
21:48to make sure that all the columns of the Parthenon looked exactly the same
21:52as well as they were able to do
22:06and they were able to do it
22:06without these bosses
22:07the only way Konstantinos and the team
22:09can lower the drum into place
22:11is to use modern equipment
22:16they tie the ropes tight around the sides of the drum
22:21but keeping the stone level is no simple task
22:25they're trying to lift it horizontally
22:27because it has to be positioned horizontally to the other drum
22:32it takes the team two days to place the drum safely into its original position
22:37and take the entrance gateway a step closer to completion
22:50the buildings on the Acropolis are over 2,400 years old
22:57Greece is still one of the most seismically active areas in the world
23:01with few other structures lasting so long
23:10so what's the secret?
23:13how have these ancient temples survived?
23:20perched high above the city of Athens
23:23the ancient temples of the Acropolis
23:25including the majestic Parthenon
23:27are an engineering mystery
23:32they stand in one of the most seismically active countries in the world
23:38recent earthquakes have demolished modern buildings in the city
23:46so how have these ancient temples survived for over 2,000 years?
23:54seismologist Yannis Kalageris monitors seismic activity on the Acropolis
24:02this is a typical installation site of the accelerographic array of the Acropolis
24:08here you can see the accelerograph
24:12this accelerograph, one of 10 positioned across the site
24:15measures how much the ground shakes
24:18we are now connected to five instruments
24:23when he looks back at the data
24:25Yannis discovers that during earthquakes
24:28something strange happens here at the Parthenon
24:32this is a typical record of a small earthquake
24:36a local earthquake
24:39the recording shows that the foundations of the Parthenon
24:42shake less than the ground in the surrounding city
24:47but why is this happening?
24:49what is special about this place?
24:52the difference is because of the local characteristics
24:55by the geology of the site
24:59the rock itself is solid
25:01but the city around it is built on loose soil
25:04that vibrates strongly in an earthquake
25:07the Parthenon is built on limestone
25:10it's more steep, more rigid
25:15it appears that the Parthenon's foundations
25:18built directly on solid rock have helped it survive
25:24but this alone doesn't explain how these temples have stood firm against earthquakes
25:31the biggest clue to what makes these structures so special hides inside their stones
25:40blow the Parthenon apart and you won't find an ounce of mortar to bond the marble together
25:51instead there are mysterious slots in the blocks and inside them, iron clamps
26:05in between the column drums there are wooden wedges and pins
26:13these pieces of iron and wood help protect the temple from earthquakes
26:18but how do they do it?
26:26civil engineer Zanis Kantaius works with the restoration team
26:31he thinks the ancient Greeks did something clever when they installed these connecting pieces
26:38the clamps were placed in sockets that were carefully carved on the top side of the blocks
26:46he's noticed that ancient builders deliberately cut the holes larger than the clamps
26:52the gap between the clamp and the socket was covered with lead
26:56which was melted and poured inside the socket
26:59you can still see here part of the lead saved
27:04the lead seals the iron clamps from the air and stops them from rusting
27:09but it also plays a critical role in an earthquake
27:12lead since it is a much softer material would absorb part of the stresses
27:18during an earthquake the soft flexible lead allows the marble blocks to move
27:23while the clamps stop the walls from falling down
27:28of course it worked very well
27:30the lifetime of the monument is a great proof of it
27:36the system that protects the columns is even smarter
27:42when they pulled the columns apart archaeologists found pieces of wood 2,400 years old and amazingly well preserved
27:53the segments are called empolia and polos
27:57column drums were connected to each other by a set of three wooden components
28:01two empolia and one polos
28:04the polos would be placed inside the hole of the two empolia
28:09and this would be the connection of the drums
28:13the way the wood pieces work is ingenious
28:21without them a big quake could shake the columns out of alignment until they collapse
28:29but the empolia prevent this
28:32they sit right in the middle of the drums and act like soft wooden joints
28:40their special shape lets columns wobble in a quake
28:44but always keeps the drums in line
28:50that means they don't collapse
28:54so when the earth stops shaking the Parthenon lives to see another day
29:07archaeologists even have found proof the concept works
29:12we're lucky enough to have an example of how a lateral displacement between two drums has a result in the
29:22shape of the polos
29:23the polos was sheared
29:27has stayed in this condition
29:29and preserved extremely well
29:34the wood held the stones together
29:37it twisted but didn't break
29:40the ancient greek way of building was so good that the team restoring the acropolis still uses the same techniques
29:49where ancient stones are missing the team replaces them with new marble
29:56today the restorers are laying a new marble block on the wall of the cellar
30:00the temple sanctuary
30:06architect Rosalia Christodalapalu monitors the operation
30:11we are going to have a trial position in of this marble
30:19to join the blocks the ancient Greeks used dowels made of iron
30:25today restores use titanium because it won't rust
30:30and instead of coating the dowel in lead they cement it in place
30:35every stone has one dowel to strengthen the stone against an earthquake
30:42the mortar is a special weak mix
30:46in an earthquake it will crumble
30:48allowing the blocks to move
30:50just like the lead did
30:55after months of preparing the stone
30:57it takes the team just 10 minutes to place it in its final position
31:04they hope that by copying the tried and tested ancient methods
31:07it will sit in this same spot for centuries
31:19thanks to ingenious anti-earthquick devices
31:23the Parthenon still stands
31:25two and a half thousand years after it was built
31:31now modern researchers are able to study its walls close up
31:37they've discovered new evidence to solve a persistent mystery
31:42what did this iconic building really look like?
31:51to construct the amazing acropolis
31:54Greek builders had to transport vast amounts of marble to this site
31:59lift thousands of blocks onto its walls
32:04and carve dozens of exquisite columns
32:08but what they did next is shrouded in mystery
32:14how did they complete these buildings?
32:17and what did they originally look like?
32:23chemical engineer Eleni Aghelikopoulou is scouring the Parthenon forever
32:31in this tower
32:32she has just a few clues
32:33but one of the best is hidden in this tower
32:37it's part of a mosque built inside the Parthenon in the 16th century
32:44it's possible to see part of the older Greek temple through this gap in the wall
32:50in this area some blocks of the tower were removed
32:54and we can see very clearly the fine carving that were used to decorate this area
33:00with the eggs and the darts
33:02if we look more closely we can see very clearly some traces of blue-green color here
33:09so it seems that there is a decorative pattern that is repeated
33:15the ancient Greeks it seems didn't leave the marble bare but colored it with bright paint
33:22if so, how much of the building was painted?
33:27the scaffolding on the Parthenon allows researchers to access places they wouldn't normally see
33:34they've discovered more traces of ancient paint on the corner of the west pediment
33:39in this area we can clearly see the red color and there is a pattern of heart-shaped leaves here
33:46and in between them traces of red color that has the shape of hearts
33:52this is a typical decoration
33:55nearby Eleni has discovered a faint clue to how an ancient artist prepared the marble
34:01in this area of the Cornish block we can see clearly the decoration pattern here
34:09and if we look more closely we can distinguish the incisions that were used to do the pattern
34:16and then on top of it to apply the pigments during the classical period
34:23combining these discoveries with ancient descriptions of the Parthenon
34:26archaeologists are able to recreate what the temple originally looked like
34:36two and a half thousand years ago the Parthenon would have been an imposing site
34:48inside its inner sanctuary was a stunning display of shining marble and rich color
34:54the cloak and armor of Athena forged from over a ton of dazzling gold
34:58and her limbs carved in gleaming white ivory
35:04paint in vivid colors adorn the ceiling
35:13and at the entrance elaborate carvings showed scenes from Greek myths in such glorious color
35:18it's hard to imagine it today
35:31but despite all the evidence of color a mystery remains
35:36the surface of marble is hard and glossy
35:40paint doesn't easily adhere to it
35:43so how did the Greeks get their paint to stick
35:50Euphrosini doxyitis investigates ancient methods of painting
35:54she thinks the secret was wax
35:58you have the beeswax
36:00it's very pure and it smells beautiful
36:02and you melt it with a gum from the mastic tree
36:06and it's a resin
36:12to make the special paint
36:14Euphrosini melts the gum with beeswax
36:18then adds a pigment to give it color
36:23next she marks out the pattern
36:25I think for sure the stencil was used for the drawing
36:29and this is very hard to carve
36:31this is like the Parthenon marble
36:35precision is very important
36:37it leaves a very nice groove
36:39which helps you can be able to control the wax
36:46Euphrosini must work fast
36:47as the wax cools it solidifies
36:51ready here
36:52and I'm trying to very quickly apply it in the stencil
36:58the heat helps bind the paint to the marble
37:02burning it in makes it bond so well
37:05because it excludes the humidity
37:07it makes the wax seal the marble
37:10and become one body with it
37:13using this technique to paint the Parthenon
37:16would have required great skill
37:19the painters had to be even better than the sculptors
37:23especially on the Parthenon
37:25you didn't go near the place if you weren't a very very tough craftsman
37:31the finished paint work on Athena's great temple would have been outstanding
37:44most of the paint on the Parthenon has faded away
37:48can archaeologists solve the mysteries of the underlying stone before they are undetectable?
38:00Centuries of attack have left the marble vulnerable
38:07in the 17th century cannonballs blasted out these craters
38:19but that was a minor incident compared to the temples long history of destruction
38:28in 267 AD invaders burned down the roof
38:34through the centuries the statue of Athena over a ton of ivory and gold has disappeared
38:46then Christians turned the Parthenon into a church and rip the statues to pagan gods off the walls
38:57and in 1687 a gunpowder explosion blew the heart out of the building
39:07even today the buildings on the Acropolis are still under threat
39:14conservator Anastasia Panu leads the battle to save them
39:18as you can see the situation is very bad
39:24we have decay from atmospheric factors, biological factors
39:29we have a detachment actually of the fragments
39:33so we lose the marble
39:37an escalating problem comes from inside the stones themselves
39:43when engineers last restored the building 90 years ago
39:46they inserted new iron clamps to hold the blocks together
39:52but they coated them in poor quality lead
39:57as the clamps have rusted they have expanded cracking the ancient marble
40:01it actually makes cracks and then fractures the marble
40:07and sometimes a big piece of marble detach from the main blocks
40:13due to the iron clamps
40:18so far the team has removed over 900 iron clamps from the Parthenon
40:22and replaced them with clamps made of titanium
40:26a metal that won't corrode
40:35where essential pieces of the original marble are missing
40:38the restoration team must replace them
40:42carving the missing half of the marble block takes tremendous skill
40:48a stonemason must carefully copy a plaster cast replica of the missing piece
40:54he uses this measuring tool to identify areas of stone that need to be removed
41:03next comes the detailed work that ensures a tight fit
41:09the mason paints the old block in mud
41:13he then pushes the two stones together
41:19dots of mud on the new stone identify areas he needs to chisel away
41:25the final piece will be a perfect fit
41:32right now the new white marble on the Parthenon stands out
41:37but over time it will fade to blend with the old
41:42the new marble on this temple restored 35 years ago has already started to fade
41:49it will eventually match the original
41:58two and a half thousand years after it was built the Acropolis is still giving up its secrets
42:07helping us unravel the mysteries of the ancient Greeks
42:10helping us unravel the mysteries of the ancient Greeks
42:15the more we discover the more amazing this ancient citadel becomes
42:30its hero structure the mighty Parthenon
42:36built to worship an ancient goddess
42:40is the crowning achievement of one of the world's greatest civilizations
42:52it remains one of the most awe-inspiring ancient wonders ever built
42:56the family that comes to eternity
42:57America
42:57if you like this, you know, and immediately
43:00you can advance your faith in your death
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