00:00Medieval siege tactics frequently involved sappers undermining castle stone walls.
00:05Gravity-fed cisterns discharged scalding fluid directly into subterranean enemy excavation galleries.
00:13Defenders actually funneled water into subterranean counter tunnels to flood enemy sappers.
00:19Castles occasionally featured drainage systems designed to channel wastewater down to undermine sapper tunnels.
00:26Historical engineering analyses indicate that some medieval water systems directed runoff to counter sapper tunnels.
