The most famous of ancient Rome's monuments,
Colosseum was begun in AD 70 by emperor Vespasian and inaugurated
in AD 80 by with a program of games and shows that lasted 100 days.
The gladiator fights that took place in the arena were popular
forms of entertainment with the Romans. You can find a few of
their followers outside the Colosseum. They don't fight to their
death anymore but rather pose for pictures.
By the 15th century the Colosseum has become a quarry for building
materials. In 1749 Benedict XIV declared it sacred in the memory
of the many Christians that died here (although there is no
historical data to support the belief that Christians were
martyrized in the arena). Once it was declared sacred, its
restauration began (and still continues).