Rome’s great gladiatorial arena is the most thrilling of the city's ancient sights. Originally known as the Flavian Amphitheatre, the 50,000-seat Colosseum (Colosseo) was inaugurated in AD 80 and used to stage spectacular gladiatorial games in front of baying, bloodthirsty crowds. Two thousand years on and it's Italy's top tourist attraction, drawing up to five million visitors a year. Built by the emperor Vespasian (r AD 69–79) in the grounds of Nero's palatial Domus Aurea, the Colosseum was completed in AD 80 after eight years' construction. To mark the occasion, Vespasian's son and successor Titus (r 79–81) held games that lasted 100 days and nights, during which some 5000 animals were slaughtered. Trajan (r 98–117) later topped this, holding a marathon 117-day killing spree involving 9000 gladiators and 10,000 animals.