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.

Built between 1937 and 1939, the fort covers the Swiss end on the Mont d'Or railroad tunnel and the Joux valley.

The Fort de Pré-Giroud is located to the east of Vallorbe, in a steep hillside facing north, towards the Jougnes gap.

[1] It is part of the Border Line defenses built by Switzerland in the late 1930s, prior to a shift in Swiss priorities to the National Redoubt in the Alps.

[4] These were added in 1941, along with barbed-wire entanglements, stated to be lessons learned from the successful German assault on the Belgian Fort Eben-Emael.