Housed in the former Bishop's Palace, a 13C-18C architectural complex, it features the ruins of a Gallo-Roman house standing against a 3C rampart, as well as ex-votos from the same period. Fine medieval statuary. Works by Senlis-born historical painter Thomas Couture (1815-1879) are exhibited in the restored chapel he used as a studio. The artists known as the "Modern Primitives" are grouped around Séraphine Louis, nicknamed Séraphine of Senlis.