Teatro Romano (Roman Theatre) was built in the late reign of Roman emperor Augustus, some decades after the foundation of the city (25 BC). It was extended two centuries later. The theatre occupies three blocks annexed to the ancient city walls, along the Roman main road structure occupied an area of 81 by 64 meters. One can still identify its semi-circular tiers, the orchestra pit, and the stage wall, which was once raised with decorated columns, marble and statues. The theatre could hold as many as 4.000 spectators.

Today the southern façade - perforated by arches and windows - still remains. The wall has a height of 22 meters. The cavea was enclosed in a rectangular-shaped wall including the remaining southern part. This was reinforced by buttresses each 5.5 metres from the other, and included by four orders of arcades which lightened its structure.

In the Middle Ages, the original function of the theater was forgotten and different constructions began to grow around it. Their demolition was proposed in 1863 , but the process finally completed between 1933 and 1941.