A monumental complex of buildings was also begun around the spring of Nemausus in the Augustan period. This included a collecting pool, nymphaeum and temple precinct. The sanctuary buildings were enclosed to east, south and west by a large portico. Adjoining the west portico is the "Temple of Diana", a building unlikely to have been a temple, although its unusual character makes its purpose uncertain. The façade, with two large niches on either side of the entrance steps, fronts a central hall, barrel-vaulted in stone, with engaged pilasters dividing the sides into five bays containing niches set in aediculae with alternating triangular and segmental pediments. At the west end, opposite the entrance, there was a chamber, three metres square, and passages leading to an upper floor. The use of cut stone vaulting and the aediculae are more typical of Roman architecture in the East, whence the builders therefore seem to have come. The ornament indicates a date in the 2nd century AD.