Fort de Joux

The Fort de Joux or Château de Joux is a castle, transformed into a fort, located in La Cluse-et-Mijoux, in the Doubs département, in the Jura mountains of France. It commands the mountain pass "Cluse de Pontarlier".

During its long history, Fort de Joux has gone through successive transformations. The first structure, in the 11th century, was made of wood. In the next century the lords of Joux rebuilt it in stone. It passed, along with all of Franche-Comté, into the hands of Burgundy, and then the Hapsburgs and the Spanish. It was finally regained for France in 1687 by Louis XIV.

While others have improved or at least repaired the castle during the course of its history, Fort de Joux's most famous remodeler was Vauban, who modernized it in 1690. The Austrians captured it in 1814. Later, the construction of the forts at Larmont during the 19th century provided reinforcement. In 1879, Captain (later General) Joffre, then a military engineering officer, modernised it and transformed it into a fort.

It served as a prison for successive French governments between the 17th and 19th centuries. In this capacity, Fort-de-Joux is best known for serving as the site of imprisonment for Toussaint Louverture, who died there on 7 April 1803, Mirabeau, and Heinrich von Kleist.

In addition to being employed as a prison, Fort-de-Joux has played a part in the defence of the region up until World War I.

The fortress currently houses a museum of arms that exhibits more than 600 rare weapons dating from the early 18th to the 20th centuries, including a rare 1717 rifle. The castle also has a well which, at 120 m, is one of the deepest in Europe.

Since 1949, the French Ministry of Culture has listed Fort de Joux as a monument historique.