The Colosseum is an amphitheatre built in Rome under the Flavian emperors of the Roman Empire. It is also called the Flavian Amphitheatre. It is an elliptical structure made of stone, concrete, and tuff, and it stands four stories tall at its highest point. It measures 620 by 513 feet (189 by 156 metres) and could hold as many as 50,000 spectators. The Colosseum was famously used for gladiatorial combat.