Le Perthus became French territory after the Treaty of the Pyrenees (1659). The Spanish captured Bellegarde in 1674 and began work on new fortifications in 1675. These were not very far advanced when the place was recaptured by the French. In 1678 Vauban designed for Bellegarde a strong pentagonal fort with a detached hornwork extending southwards towards the frontier.
The defences consist of a five bastioned trace, with an upper tier and a lower tier. In front of the more vulnerable sections of wall, there is a ditch. There are three demi-lunes, again only on the more approachable sides of the fortress - on the east there is a sheer precipice.
During the War of the Pyrenees, the fortress was besieged in May - June 1793 by the Spanish and then by the French (in 1794).
During World War II, the fort was used as a holding prison by the Gestapo for escaped prisoners of war and enemy agents.
The fort is open to the public between June and September only and includes exhibits on the history of the fort, its archaeology and the surrounding area.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.