The Cathédrale St-André, a Unesco World Heritage Site prior to the city's classification, lords it over the city. The cathedral's oldest section dates from 1096; most of what you see today was built in the 13th and 14th centuries. Enjoy exceptional masonry carvings in the north portal.
Even more imposing than the cathedral itself is the gargoyled, 50m-high Gothic belfry, Tour Pey Berland, erected between 1440 and 1466.