Back in its ancient heyday, Italy's third-largest amphitheatre – desired by Nero, and completed by Vespasian from AD 69 to 79 – could hold over 20,000 spectators and was occasionally flooded for mock naval battles. Its best-preserved remains lie under the main arena. Wander among the fallen columns and get your head around the complex mechanics involved in hoisting caged wild beasts up to their waiting victims through the overhead 'skylights'.
