The construction of the fort du Mont-Bart, located at an altitude of 485 metres, required more than four years of work (from 1874 to 1877). With the neighbouring forts of Mont-Vaudois, Lomont, Lachaux and the Roches battery, it constitutes the defensive curtain of Lomont. A real rampart whose crossing of fires ensures a final line of resistance in the direction of Besançon.

Entirely built in cut stone, reinforced by two ditches, this imposing military structure occupies an area of 3.5 hectares. Its pentagonal shape allows it to provide 360-degree protection. It is equipped with the first Mougin armoured casemate of 155L model 1877 and two annex batteries. However, its fortifications were quickly overtaken by weaponry development. To provide resistance to new explosives, they required work until the First World War, with the construction of a gunpowder magazine cavern in the rock and the covering of its shacks.

The fort remained active until the early 1950s because it constituted an exceptional observation post on the surroundings. Abandoned, it was reinvested in the 1980s by the Association of Safeguarding the fort of Mont-Bart supported by the municipality of Bavans. The Association undertook restoration work and set up activities. Pays de Montbéliard Agglomération (the local consortium of municipalities) recognized the fort as being of community interest in 2009. After major security work, the fort was reopened to the public. It has since hosted a major program of cultural and leisure activities.