Fort du Bois dOye

Fort Bois d'Oye, also known as Fort Eblé, is situated in the commune of Bermont and was constructed between 1883 and 1886. It forms part of the second ring of fortifications around Belfort, northeastern France, designed as part of the Séré de Rivières system to address advancements in artillery technology during the late 19th century.

The fort is a large pentagonal structure built from limestone, featuring walls enclosing an open court at an elevation of 420 meters. Its strategic position allows it to overlook the Montbéliard and Delle railways and monitor neighboring forts, Fort Lachaux and Fort de Vézelois. The fort's water supply was provided by a well and cistern, while its garrison comprised 624 soldiers, 32 non-commissioned officers, and 17 officers. Initially armed with 17 × 155mm long guns, 5 × 120mm long guns, 2 × 220mm mortars, and smaller weapons, the fort was later modernized.

In 1890, a large personnel shelter was constructed north of the fort to serve as an assembly point for reserves during potential attacks on Belfort. By 1893, it became linked to other forts around Belfort via strategic railroad connections. Further modernization between 1908 and 1913 included concrete reinforcements, defensive modifications, and the addition of casemates, machine gun turrets, and gun turrets for 75mm and 155mm guns.

During World War II, the fort experienced fighting during the liberation of Belfort in 1944. It remains under French Army ownership and is not accessible to the public.