The Late Iron Age in the Rhineland area was a period of intensive social change, manifested in the development of a hierarchical system of sanctuaries. This paper discusses the social implications of this development, thereby emphasizing the role of regional and supraregional cult places as key-sites in the construction of politicized ethnic identities and associated power networks. Moreover, some interesting spatial and temporal patterns can be observed. In the Middle Rhine-Moselle area, the main sanctuaries and assembly places seem to be located in major fortified settlements (oppida) and often seem to have been the oldest elements within these sites. In the Lower Rhine region, there is no link between cult centers and fortified settlements, and at least one of the regional cult sites was situated in a forest.