Colosseum

The ancient Flavian Amphitheater was built by the Flavian emperors in 70 C.E. as a gift to the Roman people. As the largest Roman theater ever built, it was designed to house over 50,000 people, and had played host to gladiator games, plays and even public executions. Purchase skip-the-line tickets online to avoid long lines at the door, or join guided tours which allow for special access to restricted areas. While here, you might want to visit the adjacent Palatine Hill and Roman Forum as well. – Tripadvisor