This was built at the end of the 1st century B.C. Originally the cavea must have been divided into two tiered rows,
resting on top of radial constructions made of quadrangular limestone blocks. The top was crowned by a portico formed by 27 arches in opus quadratum. A podium about one metre high separated the orchestra pit from the proscenium. The structure which is visible today is due to the renovation work carried out between the 19th and 20th centuries. A fine summer season of classics is put on there every year. The objects found during archaeological excavations, coming also from other areas of town, are assembled in the nearby Antiquarium, together with explanatory pictures and captions.