Continuation of the excavation revealed that, behind the portico, the space was delimited by rooms with barrel vaulted ceilings. Three were explored along the southern side, all built in opus reticulatum with brick quoins. Inside each were ancient wells built in Greek style opus quadratum. The most interesting of these rooms was the third to the west, where in the Augustan period a monumental nymphaeum had been constructed. This had a marble paved entrance and the wall of the water tank was decorated with a fountain head, the spout in the form of a Medusa’s head, and an inscription referring to the merits of the Luccei, who financed the construction of a section of an aqueduct. The nymphaeum was also decorated with a glass paste mosaic, fragments of which were found in the layers of collapse, and with a statue resting on a fake rock of grey tufa. Two pilasters resting on richly moulded white marble bases stood to the sides of the entrance.