Fort de Pré-Giroud

The Fort de Pré-Giroud, also known as the Fort de Vallorbe, is a 20th-century Swiss fortification located in the Jura Mountains near the Swiss border with France. The fort defended the Col de Jougne at Vallorbe, one of the few points in the Jura that could be easily traversable by an invading force. It was a component of the Swiss Border Line of defenses. Built between 1937 and 1939, the fort covers the Swiss end on the Mont d'Or railroad tunnel and the Joux valley. It is armed with three artillery blocks for 75mm guns and two machine gun blocks. All are camouflaged, the artillery blocks as rock formations, and the machine gun blocks as houses. Deactivated as a military post in the 1980s, it is operated as a museum.

Source: Wikipedia