[2] The bulk of the subterranean galleries lie between Blocks 1 and 2, with branches running out to 3, 4 and 5.

[3] As Italian troops of the Forli Division advanced into France on 24 June 1940, they were bombarded by Saint Ours Haut's 75mm guns and 81mm mortars, supported by fire from Roche Lacroix, stopping the advance.

[10] After the 1940 armistice, Italian forces occupied the Alpine ouvrages and disarmed them.

[11] Immediately after the war, the Alpine region was regarded as an area of medium priority for restoration and reuse by the military.

However, by 1960, with France's acquisition of nuclear weapons, the cost and effectiveness of the Maginot system was called into question.