Colosseum

The Flavian Amphitheatre, opened by the emperor Titus in the year 80 AD in the centre of Rome, on the site of the artificial lake of Nero’s Domus Aurea. It held some 50,000 spectators on four tiers of seating, reached through 80 numbered entrances with a ticket system that could empty the building in minutes. Under the arena, the “hypogeum” housed animal cages, wooden lifts and machinery for the scenery.