The Colosseum was built over Nero's artificial lake, a bit of architectural revenge that turned his private pleasure garden into a public arena. When Emperor Vespasian ordered its construction in 72 CE, his engineers discovered they could use the drained lake basin as a foundation, cutting construction time in half.

At its height, this four-storey amphitheatre could flood for naval battles, though most days it hosted less aquatic entertainment. Underground, a complex system of elevators and trapdoors could hoist wild animals, gladiators, and scenery through the arena floor. After Rome fell, the Colosseum became a medieval fortress for the Frangipani, a noble family, then a source of building materials as locals carted off its limestone for their own construction projects.

VoiceMap's self-guided audio tours trace the Colosseum's evolution from gladiatorial arena to medieval fortress, connecting its architecture to Rome's political theatre and explaining how a monument built for blood sport became Christianity's most unlikely shrine.