Castillo árabe de Olvera Monument · Olvera, Sierra de Cádiz, Cádiz Fortress of Muslim origin, predating the Christian conquest of 1327, crowning Olvera's historic centre alongside the church of Nuestra Señora de la Encarnación. Photo: FranFranAFV (CC BY-SA 4.0) What to see and do in Olvera