Encyclopædia Britannica, Inc.Forts can be dull, utilitarian structures, but here are four forts and one group of forts in France that are rich with significance and interest.

　　Earlier versions of the descriptions of these forts first appeared in 1001 Amazing Places You Must See Before You Die, edited by Richard Cavendish (2016). Writers’ names appear in parentheses.

　　Citadel of Île Sainte-Marguerite (off Cannes)Île Sainte-Marguerite lies half a mile (800 meters) from the Riviera town of Cannes. Until the 20th century, the fort on the island was home to many famous prisoners of the French state. The most well-known of these is the so-called man in the iron mask—a captive of King Louis XIV whose identity was an obsessively kept secret.

　　The fort was built in 1612, when ownership of the island passed to Charles de Lorraine, the duke of Chevreuse. By the end of the century, it was being used as a barracks and state prison. The prisoner known as the man in the iron mask arrived in May 1687. He stayed on the island until 1698, when he was moved to the Bastille in Paris; he died there in 1703. The prisoner was almost certainly Eustache Dauger, a valet, but the fact that his face was always covered led to rumors that his identity was more illustrious. The many theories include the rumor that he was an elder brother of Louis XIV.

　　The only man to escape from the island prison is Achille Bazaine, who surrendered to the Prussians during the Franco-Prussian War (1870–71). He was sentenced to 20 years of exile on the island in 1873, but he managed to escape to Italy after only a year. The Algerian rebel leader Abdelkader was also held on the island in the mid-19th century.

　　The fort is now home to a youth hostel and museum. Some of the original cells survive—including that of the man in the iron mask. (Jacob Field)

　　Cognac Otard is a distillery that evolved, through several iterations, from a fort built hundreds of years earlier. Cognac Otard was established in 1795 on the banks of the Charente River. (Cognac is a form of brandy made only from the white wines of the Cognac region.) The first building on this site was a fortress, built in 950 to defend the region against the Normans. In 1190 it became, by marriage, the property of the Plantagenets—the English kings. Château Cognac was rebuilt during the 15th century by the Valois family, and the future king Francis I of France was born here in 1494. In 1517 he extended and redeveloped the château in the Italian style.

　　Baron Jean Otard was born near Cognac in 1773; he was the great grandson of James Otard of Scotland, who, loyal to the Stuart king James II, had joined him in exile in France. In 1793 Baron Otard narrowly avoided execution in the French Revolution and escaped to England. Returning in 1795, he bought Château Cognac and founded the Otard distillery. The 10-foot- (3-meter-) thick walls of the vaulted cellars were ideal for aging cognac, but the Renaissance chapel was of little use to the business and was demolished. (Elizabeth Horne)

　　Fort National (St. Malo)With its ramparts, forts, towers, and castle, St. Malo in Brittany was one of France’s most heavily defended ports. The Fort National stands out among all the military emplacements, partly because it was designed by Sébastien Le Prestre de Vauban, France’s greatest military engineer, but also because it is one of the few historic buildings to have survived relatively intact.

　　The Fort National was completed in 1689 on a tiny rocky island close to the shore. It can be reached by foot at low tide, but it is otherwise cut off from the beach. It was built on the orders of Louis XIV and designed by Vauban. The work was carried out by Siméon Garengeau, with granite imported from the nearby islands of Chausey. The decision to build a fort was understandable. St. Malo was a well-known haven for privateers (semilegal pirates) and, as such, was often targeted by the victims of their activities. In 1817 the privateer Robert Surcouf fought a notorious duel outside the walls of the fort, killing 11 Prussian officers and leaving a 12th to tell the tale.

　　St. Malo was heavily bombed in World War II, but its darkest hour came in August 1944 when 380 citizens were imprisoned in the fort by German soldiers. They were left without food for six days while much of the town was destroyed, and 18 of the prisoners died. Today the fort is a popular tourist site. (Iain Zaczek)

　　Château Grimaldi / Musée Picasso (Antibes)Château Grimaldi, a substantial fortress, was built in the 12th century. It was raised on the foundations of the acropolis (high defense point) in what was then the Greek town of Antipolis. It later became the residence of the bishops of Antibes. In 1383 Luc and Marc Grimaldi from Monaco—crossbowmen in the army of Queen Jeanne of Navarre—were given the fortress and the land around it as a private kingdom. It remained in the Grimaldi family until 1608, when Henry IV bought the land, town, and port of Antibes, and the estate became part of France.

　　The fort has had many uses over the centuries. It has been home to the king’s governor, a town hall, and a barracks. In 1925, having become somewhat neglected, Château Grimaldi was recognized as a rich archeological site and was bought by Antibes Council. Renamed Grimaldi Museum, it was classified as a historic monument in 1928.

　　In 1945 Pablo Picasso visited the museum to view an exhibition of children’s paintings. He was asked by the curator for “a little drawing for the museum.” Picasso was attracted to the place and was invited to use part of the museum as a studio. He produced a great deal of work there between September and November 1946, often using unusual materials such as house paint, fiber cement, reused wood, and plates. Picasso left these works to the town of Antibes, including La Joie de Vivre, Satyr, Sea Urchins, and The Goat. These artworks formed the basis for the development of the fortress into the Picasso Museum. (Elizabeth Horne)

　　Verdun Forts Circuit (Verdun)If, as Wilfred Owen wrote, World War I exposed as a lie the traditional view that it is a “sweet and honorable thing to die for your country,” the Battle of Verdun marked the sourest and most dishonorable point in the war. The battle, which began in February 1916 and lasted until December, resulted in some 300,000 deaths.

　　Before World War I, Verdun, in northeastern France, was the strongest point in the country, surrounded by a string of mighty forts. The city was a natural target for the Kaiser’s armies. Knowing that the French would do all they could to defend their historic forts, the Germans poured hundreds of thousands of men into their attack. From February to July 1916, the French were pushed back in some of the bloodiest fighting the war was to see. The other Allies, realizing the trouble the French were in, attacked at the Somme, partly to take German troops away from Verdun. From then on, the German forces were stretched, and the French general Philippe Pétain and his men were able to recapture their forts from the Germans.

　　Douaumont and Vaux, two of the main forts, are preserved and accessible to visitors, as are tunnels and galleries of the underground citadel. Numerous French and German cemeteries and memorials are on the Verdun battlefield. The Douaumont Ossuary contains the remains of many thousands of soldiers. (Oscar Rickett)