Olvera Castle, locally known as Castillo de Olvera, lies on a rocky cliff in the center of the town with the same name in the province of Cádiz in Spain.
The first fortress at this site was built by the Moors, probably during the 12th century to defend the border of the Nasrid Emirate of Granada against the Kingdom of Castile. Around it the medieval town of Olvera grew up.
In 1327 Olvera Castle was taken by the King of Castile, Alfons XI. The Christians then completely rebuilt the old Moorish fortress into the castle we see today. The castle has an irregular plan, adapted to the shape of the cliff, resembling an elongated triangle. The rectangular keep has two storeys covered by a barrel vaulted ceiling. The castle is also equipped with a gateway protected by a barbican, curtain walls with a parapet walkway and turrets, a subterranean enclosure and two cisterns.
In 1492 the War of Granada ended in a victory for the Kingdom of Castile and Olvera Castle lost its military value.
Olvera Castle can be visited for a small fee. When I came by it was out of season, so sadly it was closed. Too bad, it looks great.
I guess that from Olvera Castle you can easily see Hierro Castle to the north.