Ouvrage Les Aittes, Military museum in Cervières, France

Ouvrage Les Aittes is a mountain fort at 2,029 meters altitude featuring three infantry blocks, one observation block, and a 215-meter-long tunnel carved into the rock. The entire structure was excavated directly into the mountain.

The fort was completed in 1937 as part of the Maginot Line's Alpine extension. During the Italian invasion of 1940, it housed 92 soldiers defending the mountain border.

The fort's name comes from the hamlet of Les Aittes, upstream of Cervières in the Cerveyrette valley. Nearby stands the Mur des Aittes, a masonry wall 328 metres long and 2.5 metres high, built in 1898-1901 by the 159th Infantry Regiment and pierced with more than a hundred firing loopholes. The Maginot ouvrage was built to back up this older barrier.

The fort opens for guided tours during summer months, allowing visitors to explore the underground tunnels. Sturdy shoes and warm clothing are recommended since the tunnels stay cool year-round.

The entry block's machine-gun embrasure was served by MAC 1924/1929 machine guns with a practical range of about 600 metres and 7,000 rounds in store. A radio post stood in the entry block, its antenna running along the facade. Water came from a captured spring and was held in two 7,200-litre tanks in the barracks.