Fort Louvois, known locally as Fort Chapus or Fort du Chapus, was built between 1691 and 1694 during the reign of Louis XIV on the Chapus islet. The fort is located about 400 meters offshore opposite the citadel of Château d'Oléron on the island of Oléron. The fort was positioned so that a crossfire from the château and the fort would control the Pertuis de Maumusson (Passage of Maumusson) and impede access to the Rochefort roads from the south. Fort Louvois only saw action towards the end of World War II when bombardment greatly damaged the fort, necessitating later restoration.
Since 1972 the fort has been the site of a museum of oyster farming, and there are oyster beds next to the causeway that joins the fort to the shore. The fort also houses a permanent exhibition that describes the history of the fort and that contains models of fortifications on the Charente coast. During the summer a shuttle boat that operates during high tide takes visitors to the fort; at low tide the fort is accessible via a causeway.
Fort Énet is located near the city of Fouras in the Charente-Maritime region, and can be reached on foot by a causeway during low tide. The fort was built on orders of Napoleon starting 1810 and completed between 1848 and 1850. Initially called "Enette", it was built to block the passage between the Ile d'Aix and the coast, although it mainly served as a prison for convicts transit.
Fort Boyard is located half way between Aix and Oléron Island in the Pertuis d'Antioche straits, on the west coast of France. The fort was started in 1801 and was completed in 1857 under the reign of Napoleon Bonaparte, although he never saw the finished construction, as he left the Ile d'Aix to go into exile. But progress in artillery, which advanced quicker than the building work, rendered it useless even before it was finished. It cost the equivalent of more than two hundred million Euros today.
Fort de La Prée
Fort de La Prée is a star fort near the eastern end of the Ile de Ré, built in the 17th century. In 1625, the French officer Toiras led the Royalist troops when they captured Ré from the Huguenots under the command of admiral Duke of Soubise. After his victory, Toiras received the title of Count, and became Governor of Ile de Ré. It was he who built Fort de La Prée.
Fort Îles Saint-Marcouf
In the Baie de la Seine region of the English Channel off the coast of Normandy lies two small uninhabited islands called Îles Saint-Marcouf. The larger island, île du Large, is 500 metres east of the smaller île de Terre and contains a fort built between 1803 and 1812 under the orders of Napoleon. The islands are now protected nature reserve with restricted access.
Fort-la-Latte is a 14th-century castle fortified with bastions in the 1700s. It is located southeast of Cap Fréhel on the Emerald Coast of Brittany, and is considered one of Brittany's finest fortifications. The castle has been a popular location for file shoots including The Vikings (1958) and Ridicule (1996).
Fort Lupin, also called Fort de la Charente, is located on the southern bank the Charente river, built on a rock midway between the river mouth and the first meander toward Rochefort. This 17th century fort is an example of the very elegant fortification design of a series of forts built along the French shores, consisting of a semi-circular battery for use against ships, a cenrtal tower and a front to protect the landward side.