Prehistoric and Gallo-Roman collections bear witness to two important periods in St-Marcel's history: firstly, an impressive display of Magdalenian artefacts (14 000 BC; and secondly Gaulish items, pertaining to artisans and merchants, funerary rites and religious practices. Don't miss the archaeological crypt where visitors can see the imposing remains of the north ditch, an artisanal area, and excavations (including a domestic altar which remains where it was discovered in 1986).