The Colosseum has been a symbol of Rome since 80 AD, and today it’s a top monument in Italy. Some 50,000 spectators once gathered in the amphitheater’s tiered seats to watch gladiatorial games, and though parts of its original marble facade were pilfered over the years to build the likes of St. Peter’s Basilica, the Colosseum remains remarkably intact 2,000 years later.