On the west side of the main street lies the Gymnasium. The building is organized around a court surrounded by Doric porticos, with a length of at least 80 m on the southern side, which has been the object of excavations. The portico, 5,50 m high, was constructed at the beginning of the 1st century AD by the emperor, as an inscription on the architrave states. It collapsed during an earthquake in the 7th century and was covered by a calcareous deposit.