Secrets of the Colosseum

NOVA: The Colosseum is a monument to Roman imperial power and cruelty. Records of the games staged there describe seemingly impossible acts, such as beasts appearing on stage and water flooding the arena to recreate major sea battles. Experts have been sceptical that the Romans could achieve these feats, so a team of modern builders and engineers test their theories by building a trap-door-and-pulley system in an effort to replicate the potential innovation and ingenuity of the Romans. Ⓢ