The collegial Notre Dame des Marais was built on the swamps of the Morgon River (river crossing the city) where, it is said, shepherds discovered a statue of the Virgin.
Parish Church during the Middle Ages, extended during the XV century by the addition of the flamboyant Gothic facade and the bell-tower, thanks to the support of Pierre and Anne de Beaujeu it became 'collegial" in the XVII century. The bell-tower was destroyed in 1566 by a fire and rebuilt in 1862. It looks out over the city from a height of 80 meters. Numerous gargoyles can be found on the north wall; The most well-known represents luxury and always attracts the curiosity of visitors. Inside one can find beautiful stained glass windows from the XIV and XVI centuries and the pulpit from the XVII century.