A must-see for anyone visiting the island of Oléron.
Richelieu ordered its construction, which began in 1630 on the remains of the old medieval castle. The work was led by the engineer Pierre d'Argencourt, who ordered the first bastion, and Louis Nicolas de Clerville later modified and enlarged the structure.
The citadel and the town were completed in 1700 under the orders of Vauban. During this final phase of construction, part of the old village was razed to make way for a new fortified town, built on a grid pattern around the parade ground.
A fortress with a defensive function, the citadel also housed disciplinary bodies, civilian and religious inmates during the Reign of Terror, and political prisoners in 1870.
On April 17, 1945, an aerial bombardment destroyed many parts of the citadel. From 1959 to 1970, an initial restoration began. The stronghold was restored from 1988.