Ancient Romans flocked to this massive amphitheater by the tens of thousands, eagerly awaiting a bloody spectacle. As each gory show played on, the audience was sure to stay cool-thanks to a billowing canopy that protected them from the blazing Mediterranean sun.
But how did the Roman builders completely cover the Colosseum? Even today's engineers don't usually attempt to roof an entire arena- and those that do rely on modern materials. Not a shred of the ancient roof has survived, so NOVA tries out two competing concepts. Every clue is precious-whether below the streets of Rome or in a puzzling painting from Pompeii.
It's one of the most mysterious places on earth: a strange circle of stones, standing over the plains of England. Legends have linked Stonehenge to everyone from pagan druids to Merlin, but science has recently determined that this enigmatic temple was built by early Britons some 4,500 years ago. The question of how has been a matter of mere conjecture...until now.
NOVA sends archaeologist Julian Richards, engineer Mark Whitby, and stonemason Roger Hopkins (of This Old House) on a mission: to move, raise, and cap a Stonehenge-like structure, armed only with Stone Age tools.