Salbert by Chalonvillars

Fort du Salbert, also known as Fort Lefebvre, was built between 1874 and 1877. It was named after General François Joseph Lefebvre. It forms part of the Séré de Rivières system fortifications in the fortified region of Belfort in northeastern France. It is located at the summit of Salbert hill to the northwest of Belfort.

Essert is a commune in the Territoire de Belfort department in Bourgogne-Franche-Comté in northeastern France.

From 1949 to March 10, 1967, France's military operated within the NATO command structure, integrating its air defense system (the Défense Aérienne du Territoire (D.A.T.)) with that of NATO through the indirect use of American aid funds. Between 1953 and 1958, the D.A.T. built a radar station in an old troops shelter (in French : abri-caverne) near the fort, called Ouvrage "G".