Spain

Playa de las Catedrales
Also known locally as 'As Catedrais' or 'Cathedral Beach' this is a beach just west of Ribadeo on the Galician coast. It is famous for its remarkable rock formations, sea caves, and magnificent cliffs, but it is only accessible at low tide. The 30 metre high arches formed by natural sea erosion can be likened to cathedral flying buttresses, hence the name. The beach has been declared a National Monument by the Galician Ministry for the Environment.
( Firefox users with old graphics cards may need to enable 'WebGL' ) See here
Flag of Galicia