The Oignies Priory treasury, saved from 1940 air raids, is housed in one room. Exhibits include early-13C evangelistaries and reliquaries by the Mosan monk Hugo d'Oignies, whose delicate skill can notably be seen in the black-background medallions with filigree and leaf decoration amid tiny hunting scenes. On your left, beyond the theatre stands the Tour St-Jacques, used as a belfry since the 18C.