Forte di Champlas Séguin, Military fort in Cesana Torinese, Italy.

Forte di Champlas Séguin is a mountain fort in Cesana Torinese with a five-sided shape and an underground system of tunnels, gun positions, and barracks. Thick stone walls and defensive ditches surround the main area, though vegetation now covers much of the remaining structure.

Built in the 1890s, the fort defended the national territory against a possible French attack coming from the Colle del Monginevro, and was the largest work of the Piazza di Cesana after the Batteria dello Chaberton. Disarmed in 1915, by the eve of the Second World War it served mainly as a magazine of black powder and shells. On the night of 6 June 1944 the partisans of the "Serafinolo" band blew it up to keep the explosives from German formations; the 1947 peace treaty with France then required the demolition of artillery works within 20 km of the border.

The fort's name comes from the Champlas Sèguin hamlet of Cesana Torinese, just below the site. Its guns faced the Col Bousson and Col Bourget passes, the routes a French attack from the Monginevro would use. In June 1944 partisans of the "Serafinolo" band blew up its powder magazine to keep the explosives from German troops.

The site sits high in the mountains and requires good physical condition to reach and explore. Paths through the fort are overgrown and uneven, so sturdy shoes and careful footing are necessary.

The fort housed six large cannons positioned to cover nearby mountain passes, allowing defenders to control multiple approach routes from one position. This gun placement strategy made it a key chokepoint for Alpine defense.