On the other side of the city from the theatre was the other great venue for spectacles, the Amphitheatre, or Arena, which can be dated to the 3rd decade AD (restored many times since the Middle Ages). The third largest antique amphitheatre in Italy (after Rome's Colosseum and the arena at Capua), it is surrounded by an almost intact two-tier range of superimposed arches. Four bays of the original outer perimeter wall survive. The arena floor is large (73 x 44 m) and, together with the cavea, provides seating for over 20,000 spectators. It now hosts the annual outdoor opera season.