The project of entrenched camp between Cuneo and Roya responded to a strategic need born in 1860, annexation of the County of Nice to France, placing the French-Italian border south of the towns of Tende and La Brigue.
It was initiated in 1871, but built and modified ten years later. The opening of the Tende’s col road tunnel in 1882 made it necessary to set up a military control system for this facilitated passage to Piedmont.
The “entrenched camp” of the Tende’s col is organized on two lines of defense.
1) Next to the ridge, four batteries (strong) on 7 km: from west to east, the forts of Giaure, Pernante, Central and Pepin.
2) Below Roya side, on both sides of the road leading to the tunnel, two batteries distant 3 km in advanced position: Forts Marguerie and Tabourde.
A large barracks are located near Fort Central.
The site of the central fort was launched in 1881 and completed in 1883. The construction of the five other works followed.
They are stone masonry works, typical of their time, surrounded by moats and accessible by a drawbridge, roughly rectangular or pentagonal, with several fronts of attack towards Roya valley, armed with guns and protected by glacis (sloping faces and weeds), as well as a “front de gorge” (facing the enemy rear facade) where the entrance and barracks are located, equipped with battlements for close defense fire. The various vaulted casemates (rooms) are connected by subterranean or masonry corridors on the surface covered with grassy protective embankments.
With the exception of Fort Central, which asserts its presence by a large Roya side façade, above the road, the accompanying works are more discreet in the landscape.
The building materials were extracted on site, mostly white limestone or granite.
During the first world war, the works were disarmed for the benefit of the Austrian front. Then, these stale forts in the face of advances in artillery were used only as ammunition reserves and for the cantonment of troops.
During the 1930s, the Valle Alpino fortification program (blockhouse infantry works for machine guns) implanted numerous batteries in the sector of Tende and La Brigue. Some were added to the former nineteenth century entrenched camp.