The survival of a ritual site from the late La Tene into the early Roman period is one of the most significant results to come from the excavations undertaken at the Frauenberg in the south-east of Noricum (Austria) between 2002 and 2004. In the La Tène D2 period a sanctuary of the type known from Manching and Gournay-sur-Aronde, for example, was established within an already existing Iron Age settlement. The development of the buildings and of the evidence for ritual practices is analysed here over five phases, culminating in the Flavian period in a temple with surrounding portico. This abandonment within the sanctuary of elements of the La Tène tradition in favour of a classical-style temple on a podium is set in the context of regional adminstrative changes in the Flavian and Trajanic periods. This is the first time that this type of development of a cult-site, from the Late La Tène into the Roman period, has been recorded in Noricum, though parallels from outside the province are known, in particular in Gaul.