The island's beach is popular in summer with visitors arriving by yacht or motorboat and there are also regular shuttles from St-Malo, although landing is only possible at high tide.

[1] Vauban fortified the island at the end of the seventeenth century, and it was used thereafter as a place of quarantine, with cargo stored in Saint Brendan's chapel.

[3] During World War II, the Germans and Italians strengthened the island's fortifications as part of the Atlantic Wall.

[5] As a result of this intense Allied bombardment, Cézembre's landscape is barren and pitted, although natural vegetation is returning.

After demining operations, the management of the island was transferred from the French ministry of Defense to the Conservatoire du littoral (coastal conservatory, an official French public operator) in October 2017, in order to further expand its natural protection and manage the historic and archaeology sites left on the island, including the ruins of chapels and burial sites.