Hourdel Lighthouse is a lighthouse on the common Cayeux-sur-Mer, it is built on the south side of the Bay of Somme, in the end the point of Hourdel.
History : The first fire date of 1840. In 1852, it fixed the port light is mounted on a stem wood of 10 m. In 1905, a new device is mounted on a metal stem and cabin sheet 10,20 m high. It was destroyed in 1944. In 1948 a cylindrical tower 18 meters of reinforced concrete and adjacent to a room service is built. It is a white and green light to three occultations every 12 seconds. A foghorn was still in service in 1987.