The Tombelaine Rock is located 2.7 km from Mont-Saint-Michel and can be reached at low tide. On its eastern part, the Folie peak rises to 45 meters. Between the 11th and 14th centuries, Tombelaine was an inevitable point of passage for pilgrims on their way to Mont-Saint-Michel: there, they found a priory and even a street with shops. The varied ecosystem of the rock allows many birds to nest there in spring. To ensure their tranquillity, the public is asked to avoid visiting the islet during the nesting period, from 15 March to 15 July.