The fort was part of the defenses that Vauban designed to protect Saint-Malo from British and Dutch fleets.
On the landward side the fort consisted of two half-bastions that flank the entrance, which is a few metres above the level of the rocks.
Cross-fire from Petit Bé and Fort Harbourg in Dinard protected the estuary of the Rance.
It became a Monument historique in 1921, but was neglected until 2000, when the city gave it to a non-profit organization rent-free to renovate it and prepare it for tourism.
The cistern had to be emptied of garbage and it now retains storm water fed into it from the restored roof of the barracks building.