The archaeological museum occupies the Présidial — a 17th-century administrative building at the centre of the old town — and contains the main collection of Roman artefacts from the excavations at Saintes and its surroundings. Mosaics, sculptures, everyday objects from Roman households, and funerary monuments give a concrete sense of what Mediolanum Santonum actually looked like as a functioning Roman city.
The collection is particularly strong on the votive objects and inscriptions that characterise Roman religious practice in this part of Gaul, and on the craftwork and commercial goods that reflect the town's importance as a trading hub. Not a large museum, but genuinely informative about a city whose Roman past tends to be underappreciated relative to the bigger sites in Provence and the south.