The castle has watched over the ramparts and countryside since the 11C. Remodelled from the 13C-16C, it has retained its splendour, in evidence from the entrance, defended by a drawbridge and robust gatehouse flanked by two large machicolated towers. St-Laurent tower provides a view over the jumble of slate roofs, revealing the narrowness of the streets. With the Argenterie and Oratoire towers, it is home to the museum's collections (sculpture, sacred art, enamels).