Ouvrage Janus

Ouvrage Janus is an underground military fortification in the French Alps that extends 900 meters across an elevation of about 2,450 meters (8,000 feet). The complex divides into eight separate blocks, each containing artillery positions, ammunition storage, barracks, and medical facilities designed to house up to 230 soldiers.

Built in 1931 as part of the Maginot Line, this fortification was designed to defend against potential threats from Italy. It served as a key defensive position along France's southeastern border during the Second World War.

The name references the Roman god Janus, symbolizing the duality between peace and war. Visitors can sense this concept reflected in how the spaces alternate between civilian and military functions throughout the structure.

Visiting this underground fortress requires good physical fitness as you climb stairs and navigate tight corridors throughout the tour. Bring warm clothing since temperatures stay cool underground year-round, and allow several hours to fully explore all eight blocks.

The site was equipped with four 95mm cannons and stands as one of the highest-elevation fortifications of the Maginot Line. This extreme altitude made it a rare choice for heavy artillery deployment during that period.

Location: Montgenèvre

GPS coordinates: 44.91150,6.71080

Latest update: December 8, 2025 21:00