Batterie de Bouviers, Fortress in Guyancourt, France

Batterie de Bouviers is a former military battery in Guyancourt, built of limestone, millstone and brick. Its gatehouse, facing the main barracks, carries a stone plaque inscribed "Batterie de Bouviers" above an arched opening closed by a metal grille, with a mortar carved on the keystone. Behind it, vaulted casemates 6 by 15 metres, separated by piers 1.5 to 2 metres thick, were covered with earth from the surrounding ditch.

Built between 1877 and 1879 near the hamlet of Bouviers, the battery was one of 18 forts, 5 redoubts and 34 batteries of the Séré de Rivières ring raised after the 1870 defeat to defend Paris. It formed an ensemble with the Fort de Villeras at Saclay and the Fort du Haut-Buc, plus five outworks. The army held it until 1932; from 1933 Hispano-Suiza leased it as a munitions factory, and the Ministry of Defence sold it in 1999.

The fortress transformed into a music venue in 2006, hosting the Café Musiques facility for performances and rehearsals within its historical walls.

The Café Musiques occupies the former barracks building, with a proscenium stage seating 450 spectators plus three rehearsal and recording studios. The gate on the northeastern facade carries the inscription "Batterie de Bouviers" and the date 1879, with a mortar carved on the keystone. The site lies in the Saules neighbourhood of Guyancourt, near the Satory plateau.

The gate's keystone carries a carved mortar, and the fronton reads "Batterie de Bouviers" with the date 1879. The name is often confused with the nearby Batterie du Ravin de Bouviers, a much smaller work sometimes called a redoubt.