The Cathedral Museum rises above subterranean vaults or cellars, which were re-opened in 1995, after many years of neglect. They have been renovated for contemporary exhibitions. There are no secure documentary references as to their original function, but they probably served as storage spaces for wine and oil; some large jars still survive. The cellars may have also been used as workshops for the maintenance of the building. Inside is a network of spaces of different dimensions. These reflect the general lay-out and basic structure of the museum's ground floor. Interestingly the remains of an old Roman wall can still be seen, a survival of a construction dating from centuries before the foundation of the seminary in 1734.
Follow this link to view the map of the Cathedral Museum Subterranean Vaults. For an architectural plan of the Vaults click here.