Phare du Plateau du Four, Lighthouse on Plateau du Four, Le Croisic, France.

The Phare du Plateau du Four is a 23-meter stone lighthouse on the Plateau du Four, a tidal islet about 6.6 km west of Le Croisic. Its cylindrical shaft is painted with broad black and white diagonal bands that spiral around the tower, and a green metal lantern room with a railed gallery sits at the top. The tower was raised by 6 meters in 1946.

The lighthouse was built between 1816 and 1821 under engineer Joseph Marie Rapatel and began operating in January 1822. In 1946, it was raised by 6 meters to improve its visibility for vessels crossing the Atlantic.

The lighthouse is visible from the shore and has long been part of daily life for the fishing communities of Le Croisic. Its black and white striped tower is a familiar sight to anyone who spends time along this stretch of coast.

The tower stands on the Plateau du Four, a tidal island about 6.6 km west of the Le Croisic coast, reached only by boat. It is not open to visitors and has been remotely controlled and unstaffed since 1983. Its white flash returns every 5 seconds and carries 18 nautical miles.

At high tide, the base of the lighthouse disappears entirely underwater, making the tower appear to rise directly from the sea with no foundation visible. This effect shifts completely with each tide, so the same view from shore looks different depending on when you look.