Little remains of the 15C castle. The ramparts dotted with 14 towers now protect the 17C church, home to a fragment of the "Holy Cross" that has been an object of devout worship since the 13C. The facade, adorned with a superb portal (1722), made of local red marble, is strikingly Baroque. The impression of verticality and strength is reminiscent of Latin-American churches. Panoramic view from the ramparts.