Islote de Sancti Petri

The ruins of an eighteenth-century castle remain on the island; the tower of the castle has been substantially rebuilt, and it is now in use as a lighthouse. It was declared ''Bien de Interés Cultural'' in 1993.

The name, Sancti Petri, also applies to the beach on the mainland, in Chiclana de la Frontera, directly opposite the island. Provided by Wikipedia