Ouvrage Saint-Gobain

Ouvrage Saint-Gobain is a military fort in Modane built into the mountainside, featuring five separate underground sections including an entrance area, infantry section, artillery zone, observation post, and support structures. These sections connect through narrow corridors and were designed to work together as a unified defensive system.

Built in 1931 as part of the Alpine extension of the Maginot Line, the fort was created to defend the French-Italian border. During World War II, it played a role in the mountain defense strategy of the region.

The fort demonstrates French military engineering through its underground network of galleries and combat rooms that show how soldiers lived and worked in tight spaces carved into the mountain. Visitors can observe the layout that reveals the daily routines and defensive strategies of the era.

Visitors should bring warm clothing since the underground passages maintain a cool temperature year-round. The guided tours involve climbing stairs and navigating through narrow corridors, requiring reasonable physical fitness.

The fort maintains a constant interior temperature of around 12 degrees Celsius, which has naturally preserved the original military equipment and artifacts found inside. This underground chill makes it one of the best-preserved examples of its kind.