This museum is housed in the caves below the old bishop's palace (17C). Its collections from prehistory and archaeological excavations show the evolution of funeral traditions: Gallic incineration wells, Christian sarcophagi, items from Merovingian necropolises and a unique set of twenty taurobolic altars, dedicated to Jupiter and Cybele. Other exhibits include mosaics with geometric or floral decoration, as well as a potter's kiln, ceramics and coins which evoke everyday life in Roman times.