The structure, located at the southern limit of the archaeological site, was excavated in the course of 1956, at the same time as the Thermal baths n. 1. The building, also called the “Baths of the Old Convent”, consists of three levels, including a changing room (apodyterium), equipped with a masonry pallet with triangular shelves for storing footwear, a frigidarium, (cold room) with two basins pools and a mosaic floor, two tepidaria (warm room) and a caldarium (room containing warm water for bathing ) with two apses, thus forming a circular route.
The water supply of the baths was ensured by the presence of a large cistern covered with earthenware, supported by a vaulted room.

The mosaic floor of the frigidarium, consisting of white, black, yellow and red tiles to create geometric patterns, was dated, as was the entire building, to the end of the 2^nd century AD.
Some documents report the use of the structure as a burial area in the Byzantine period; a rectangular tomb was found in the changing room. A possible reutilization of the building as a monastery, has also been hypothesized which might explain the name of “Old Convent”.