Ancient Rome's huge ampitheater, holding up to 55,000 people, was built by Emperor Vespasian in AD 80 and was the scene of many deadly gladiatorial and wild animal fights. Today you may see men dressed in gladiatorial costume as you walk between the Colosseum and the nearby Arch of Constantine, built in AD 315. On Sundays, the Via dei Fori Imperiali leading to the Colosseum is closed to traffic so it's a great place for a stroll (if you don't mind the souvenir vendors). Ticket lines can be long but there are ways to buy tickets faster. See our tips for Buying Rome Colosseum Tickets.