It’s impossible to work on a list dedicated to the best things to do in Rome without mentioning the Colosseum right off the bat. The largest amphitheatre ever built, the Colosseum (or “Flavian Amphitheatre”) was built between 70-80 AD and could hold up to 80,000 spectators. It was constructed to host gruesome performances for the public, including gladiator battles, animal hunting, executions and even sea battles, when the arena would be filled with water and ships. Today, you can wander around the underground tunnels, the arena floor and the stands. The 5th level is also open to the public and offers an outstanding 360-degree view of the theatre.