Capua is a city situated 25 km (16 miles) north of Naples, on the north-eastern edge of the Campanian plain. The amphitheatre is one of the largest in existence. Built in the time of the Emperor Augustus, it was restored by Hadrian and dedicated by Antoninus Pius. The exterior was formed of 80 Doric arcades of four stories each (but only two arches now remain).Beneath the arena run extensive subterranean passages.