Phare du fort de l'Ouest, Navigation lighthouse in Cherbourg-en-Cotentin harbor, France

Phare du fort de l'Ouest is a cylindrical masonry tower of exposed grey stone, built on the Fort de l'Ouest at the end of Cherbourg's central dike. Its white-painted upper section carries a red top, a black gallery railing and a lantern, with the name "GATTEVILLE" painted in black below the red band. The tower rises from a curved low wall of large brown and grey stone blocks pierced by small grilled openings.

A fixed white light was installed in 1853 on a 15.50-metre tower at the end of the central dike. A fixed red light followed in 1862 on a 9.65-metre turret, and the present three-group white-and-red flashing light, period 15 seconds, dates from 1896. The fort was badly damaged in the Second World War; the light was electrified in 1934 and automated in 1977.

The tower carries the name "GATTEVILLE" in black letters below its red top, a detail visible from the water. It is one of six lights marking the entrance to the Cherbourg roadstead, listed from east to west: Île Pelée, Fort de l'Est, the central dike fort, Fort de l'Ouest, the commercial port jetty and Querqueville. The fort beneath it belongs to the French Navy.

The lighthouse stands on the Fort de l'Ouest at the end of Cherbourg's central dike, a military site belonging to the French Navy, so the tower itself cannot be entered. It is best seen from the water, on harbor boat trips, or from the dike and waterfront points looking toward the fort. Two wind turbines and a fog signal are mounted on the structure.

The structure includes an audible warning system that automatically activates during thick fog or low visibility. This sound signal serves as a crucial navigation aid when visual reference alone is insufficient for safe passage.