Fort de Mons, Fort in Mons-en-Barœul, France

Fort de Mons is a first-generation Séré de Rivières fort built in brick masonry and covered with a thick layer of earth, a detached work east of Lille's fortified belt. Its ditches were swept by two caponnières, a double one to the north-east and a single one to the south-east, while the gorge ditch was flanked by two batteries. The photograph shows the long brick facade with its band of pale stone above tall arched windows and the projecting entrance pavilion with a round-arched gate.

The fort was built between 1878 and 1880 after the 1878 decree signed by President Patrice de Mac Mahon, as a detached work east of Lille's entrenched camp. In 1887 Georges Boulanger renamed it Fort Macdonald, but the decree was revoked on 13 October 1887 and the name reverted. Lille's defences were declassified in 1910; during the German occupation of 1914-1918 the fort held Commonwealth prisoners, and between the wars it housed a military pigeon-fancying unit.

Renovated by architect Gérard David and inaugurated on 2–3 June 1984, the fort now holds the municipal library, a ludothèque, a multimedia cultural space, an exhibition hall, a music school, a restaurant, a bar and an open-air theatre. It was one of twelve Maisons Folies created for Lille 2004, when the city was European Capital of Culture.

The fort was sold to the town of Mons-en-Barœul in 1972 and renovated by architect Gérard David, reopening on 2 and 3 June 1984. Its brick buildings now hold the municipal library, a games library, a multimedia space, an exhibition room, a music school, a restaurant, a bar and an open-air theatre. The entrance pavilion has a round-arched gate; the roof is covered by an earth bank.

Ludinord, France's largest board game festival north of Paris, is held once a year in the hall adjoining the fort, not in the fort itself. The fort was one of twelve Maisons Folies created for Lille 2004, when the city was European Capital of Culture.