Lately I've been reading about oppida in the late Iron Age and how they fit into the development of cities outside of the classical Mediterranean world. What I've found indicates that many of these places were not densely occupied continuously, but rather served as monumental assembly places for ritual, prestige, and governmental functions in "barbarian" Europe. Do we have any record by Classical authors of the proceedings at one of these great assemblies? Do we have any cross-cultural examples that might provide a framework to guess how they operated? Thanks for any replies.