The single-sided currently visible it is the southern one, characterized by a series of buttresses and arches, and lightened by three overlapping of windows of varying shape and size. Clearly identifiable are the steps in hemicycle, which housed the spectators (auditorium), the orchestra and the stage wall, a time full of columns, marble and statues. It is estimated that Theater could hold three or four thousand spectators. During Middle Ages there were many huddled buildings, demolished during modern work of recovery and restoration. Only in the '20s it began a first arrangement of the monument, demolishing the huts that surrounded it.