Ouvrage Roche-la-Croix, Military fortification museum in Val-d'Oronaye, France.

Ouvrage Roche-la-Croix is a military fortification from the 1930s built into a mountainside with six combat blocks connected by underground galleries. The complex includes power stations, command posts, and specialized artillery platforms positioned at approximately 1900 meters elevation.

The fortress was built between 1931 and 1936 as part of the Alpine Maginot Line to defend the French border against possible Italian attacks through the Larche Pass. It was one of many fortification points constructed in the Alps during this period.

The fort's name comes from the rock spur above Meyronnes, and its galleries still hold the fittings of daily life: a narrow 60 cm railway for hand-pushed shell wagons, a kitchen, a barracks, a sick bay and a command post. The upper tram station was linked to the ouvrage in 1937 by a rock-armoured shelter against avalanches.

Access requires advance booking through the local cultural service, and groups are limited to 18 people per visit. The paths through the fortification are steep and narrow in places, so reasonable physical fitness is needed.

Block 6, added in 1937–38, was nicknamed the observatoire de l'égout ("observatory of the sewer") and perched on a vertical cliff face below the main work to extend flanking fire toward Saint-Ours. The upper tram station stood outside the ouvrage and was linked to it in 1937 by an 850-metre 60 cm rail line under a rock-armoured shelter against avalanches.