most of the domus aurea was torn down. the lake was filled in and the land used for the colosseum. schools for gladiators and other buildings were put up in the old gardens of the domus aurea. the colossus was left in place, but nero's head was replaced. vespasian renamed it after the sun-god, helios ("colossus solis"). many historians say that the name of the colosseum comes from the statue, the colossus. usually in roman cities, the amphitheatres were built on the edge of the city.