Maginot fortification system

All the works are isolated, in full nature, more or less close to a road.

Period XX

Accessibility No

Visitable Yes

During the 1930s, the Séré de Rivières fortifications of the nineteenth century dominating the Roya river became ineffective against aerial fire. They were replaced in the context of implementation of the Maginot Line.

On the Maginot line, surface constructions are limited to concrete blocks. Their number depends on the size of the structure. Located at the back of the fire zone, an entrance block gives access to a gallery leading to the underground barracks. If a road serves it, this block can have a large door for vehicles loaded with ammunition and equipment. In this case the gate is protected from a drawbridge ditch.

One or several blocks used as shooting rooms insure the defense. Located on the slab of a dominant block, a steel bell allows observation in addition to the close defense. These battle and observation blocks are scattered on the groundside fire zone. Wells and galleries connect all the blocks, sometimes more than 30 meters deep under the rock creating a shelter from bombing.

Conditions of visit

Circulation between buildings is not designed for people with reduced mobility.
Restricted visits (danger inside buildings)

Sector of Authion
The Authion massif is snowy in winter.
In summer it is accessible by car on the D68 road from Turini pass. The Plan Caval site is on the roadside.
Hikers can also access the massif by hiking trails from Maglia Valley.
1) Plan Caval site: edge of RD 68 road
2) Beole site: edge of Maglia trail at Authion by Colla-Bassa.

Sector of the Brouis Pass
Col de Brouis is on RD 2204 road between Breil-sur-Roya and Sospel.
3) Barracks and work of Col de Brouis: along a track from Col de Brouis.
4) Col d’Agnon work: on a height overlooking the Bourgemo au Bois Noir trail, departing from RD 2204 road
5) Cougoule work: at the end of a track from Col de Brouis.


Additional information


  • Raybaud Claude, Fortifications de l’époque moderne dans les Alpes-Maritimes, Éditions Serre (collection L’Ancre solaire), Nice, 1992.
  • Mary Jean-Yves, Hohnadel Alain, Sicard Jacques et Vauviller François, Hommes et ouvrages de la ligne Maginot, éditions Histoire & collections, coll. « L’Encyclopédie de l’Armée française »: Paris. t. 4 : la fortification alpine, 2009, t. 5 : Tous les ouvrages du Sud-Est, victoire dans les Alpes, la Corse, la ligne Mareth, la reconquête, le destin, 2009.

Useful links

1) Ouvrage de Plan Caval

2) Ouvrage de la Béole

3) Caserne et ouvrage du col de Brouis 

4) Ouvrage du col d’Agnon 

5) Ouvrage de la Cougoule