an amphitheatre (=large circular theatre without a roof) in Rome which was built during the first century AD and is now one of the most famous ancient Roman buildings. Fights involving gladiators were organized there as a form of entertainment. Flavian Amphitheater in Rome, erected AD 70-82 under the emperors Vespasian and Titus. The name Colosseum was applied some time after the 8th century because of its immense size and capacity, holding some 50,000 people. Unlike earlier amphitheaters, which were nearly all dug into hillsides for extra support, the Colosseum is a freestanding oval colonnaded structure of stone and concrete. It was the scene of combats between gladiators, contests of men with animals, and even mock naval engagements. The Colosseum was damaged by lightning and earthquakes in medieval times and, even more severely, by vandals. A restoration project was undertaken in the 1990s, and in 2000 the Colosseum staged a series of plays that marked the first time in more than 1,500 years that live performances had been held there