Listed as a historic monument, the Fort Royal on Sainte Marguerite Island owes its notoriety to its most famous prisoner, the Man in the Iron Mask, incarcerated there for eleven years when the fort housed a state prison.
Built between 1624 and 1627 on the site of old Roman fortifications, the fort began as a simple fortified house. During Spanish occupation in 1635, the little fort was extended and reinforced. Winning back the island in 1637, the French named the citadel Fort Royal and added reinforcements: deeper ditches, higher outer defence walls, two half-moons joining the fort by raised footbridges (gone today) and, later, a low bastion in front of the entry gates. The military architect Vauban gave the fort its pentagonal shape flanked by four bastions.
An advanced surveillance post was added during WWII.
Inside, there is a chapel, le, the artillery storerooms including the immense wall-enclosed powder keg and the buildings for housing the troops.
Today, the fort houses the Museum de la Mer of Cannes and is open to the public. But some parts remain in ruins, overrun by the vegetation.
Fort Royal à Cannes - Île Sainte-Marguerite - 06400 Canneshttp://www.cannes.com/fr/culture/musee-de-la-mer.html