Cayeux-sur-Mer is a small town located on the southern side of the Baie de Somme and stands between two long beach areas.
Along both flanks of the town, protecting the entrance to the river, are half a dozen defensive strongpoints. There are further sites inland of the coast, including a large radar station.
Ca03 at Plage de Brighton is one of the beachfront sites to the north of the town and featured a mixture of personnel shelters including two R668 bunkers for six soldiers, a R612 casemate for a 7.5cm field gun, a Tobruk, and a V229 stand for a medium range Wurzburg Riese radar system.
The site stands in the dunes behind the beach and is largely overgrown, but you can still see many of the larger buildings next to the tracks running to the wide beach. Some of the tracks follow the lines of the extensive trench system which once linked the different positions.