Judiciously set up on a lock surrounding the old advanced redoubt of le Châtelet built in 1693
….this strongpoint was not used in June 1940 since the Italians could not reach this particularly well defended line. Prohibiting Italians to jump off either from Maurin or from Fouillouse, it was made up of an almost linear series of concrete structures blocking the valley. Built by MOM (military labour) between 1938 and 1940,it was protected by a large network of barbed wires.Strongpoint le Châtelet could have provedall its effectivenesssinceon the evening of June 22, the Alpini attempted to infiltrate through the Chillol valley with a view to by-passMaurin's strongpoint, isolating this outpost and continuing the progression towards Saint Paul enUbaye. Effectively supported by their artillery on the Pas Nord and Sud of Chillol, they succeeded in reaching the hut ofChillol lake. But two sectionsof 2ndscouts-skiers platoon,73rd Alpine Fortress Battalion commanded by Sergeant de Jeoffre were able to contain the Italian columns with the help of artillery, the latters were subsequently forced to withdraw carrying their dead and wounded.