The Provost's Castle was located where the Archbishop's Palace now stands and was destroyed in the early 19th century. Today, only the northern façade remains, consisting of a Roman wall to which well-conserved defensive elements (merlons and crenellations) were added. Of special note is the broad Archbishop's Tower, the only other remaining element of the Provost's Castle, topped with crenellations, merlons and two rows of arrow slits, whose interior includes a large room with a pointed barrel-vault ceiling.

Provost's Castle - Archbishop's Tower (inside the walls): See "Museums and monuments" for opening hours and prices