This abbey, founded in the 13C, was an important spiritual and economic centre in the diocese of St Brieuc. The façade, open-air nave, north aisle and the left arm of the transept are all vestiges of the church (13C). The long chapterhouse is a fine example of the Anglo-Norman Gothic. You can visit the cloisters and the refectory which looks out onto the sea, as well as the lower courtyard, the Bâtiment au Duc (where pilgrims lodged), the cellar beneath the refectory, and the chaplaincy where the monks received tax on salt and grain.