Ouvrage Les Rochilles

Ouvrage Les Rochilles is a mountain fortification located at about 2,420 meters (7,900 feet) in the Cerces massif with reinforced concrete blocks serving distinct military functions. The structure contains sections for infantry positions, observation posts, and an entry area, built directly into the alpine terrain.

Construction started in 1931 as an extension of the Maginot Line into the Alps, yet the project remained unfinished when World War II began in 1940. This incomplete fortification was designed to integrate with a broader network of defensive positions across the mountain range.

The structure reflects how France approached border defense in Alpine regions during the interwar decades through concrete engineering and strategic placement. Visitors can observe the physical remnants of this military thinking expressed in heavy fortifications built at high altitude.

A visit requires proper lighting equipment since the underground corridors offer minimal natural light throughout the interior passages. Sturdy footwear and appropriate clothing for high-altitude conditions are essential as the fortification sits at significant elevation.

An aerial cable system once connected this fortification to the nearby Plan-Lachat position for supply and troop movement across the difficult terrain. This connection reveals the engineering solutions developed to overcome the challenges of operating at such high altitude.