Redoute des Trois Communes

Redoute des Trois Communes is a military fort located at 2080 meters on the Authion massif, built with reinforced concrete between 1897 and 1899. The structure sits strategically in this alpine mountain landscape and stands out as a substantial fortification in the region.

The fort was built in the late 19th century as part of France's modern defensive strategy for the mountain region. During World War II, German forces occupied it until French troops retook the position in April 1945.

The fort represents a significant example of the Séré de Rivières military architecture system, showcasing how French defensive structures evolved in the late 19th century. This design demonstrates the transition from traditional to modern defensive thinking.

The fort itself remains closed to visitors, but hiking trails around the site offer views of the structure from a distance. The high elevation means weather can change quickly, so bring appropriate clothing for alpine conditions.

This fortification was among the first military structures in France built entirely from reinforced concrete, introducing modern construction methods to defensive architecture. This technical innovation was remarkable in Europe at the time of its construction and influenced future fort designs.