Ouvrage Bois-du-Four is a lesser work (petit ouvrage) in the Fortified Sector of the Crusnes of the Maginot Line. The ouvrage consists of a single large combat block without an underground gallery system, and is located between petit ouvrage Mauvais-Bois and gros ouvrage Bréhain, facing Luxembourg. A planned expansion, never carried out, was intended to enlarge Bois-du-Four into a fully equipped gros ouvrage. Bois-du-Four saw little action in either the Battle of France in 1940 or the Lorraine Campaign of 1944. It is preserved by the community of Villers-la-Montagne and may be visited.