Located by the Baptistery, the Thermal baths n. 1 were discovered by G. Pesce during the campaign of 1956. The large building, generally dated back to the 2^ndcentury AD, was built of bricks in the heated rooms, in rows of blocks of sandstone alternating with rows of bricks (opus vittatum mixtum) in the other rooms; in some rooms, at the base of the structures of bricks, there were walls built of large dry sandstone blocks that have been thought to be part of a pre-existing building, perhaps of Punic age.
The baths, in parts poorly preserved, included a dressing room (apodyterium), three heated rooms (two calidaria and a tepidarium), two praefurnia (furnaces for heating the rooms) and various service areas.

The building during Late Antiquity and the early Middle Ages suffered numerous interventions of maintenance which in part modified the appearance and the function. The caldarium and the service areas were annexed to an early Christian complex that included some rooms built to the north; a baptistery and a Christian place of worship on a hill dominated the whole area. One of the service rooms of the baths was used as a cemetery, as evidenced by the presence of the remains of thirty buried corps from the Vandalic occupation and the Byzantine period.