The position's main armament is concentrated in Block 4, a massive blockhouse designed to protect against rockfalls from higher up the mountain.

[1][2] Ouvrage Saint-Roch was built between November 1930 and June 1932, starting with a contractor named Marting and finishing with Roussel.

Two observation posts were associated with Saint-Roch, including Campoast, armed with one machine gun and twin automatic rifle positions.

[1] Saint-Roch and an associated museum are open for visitation year-round.

[8] The facilities are operated by the Association de l'Armée des Alpes,[9]