Peñafiel Castle is located in Peñafiel, Valladolid Province, Spain. The castle is more than 150 metres (490 ft) long and encloses an area about 10 m (33 ft) wide. Standing in the middle is a 20 m (66 ft) high three storey keep.

Fernan Gonzalez began construction on the Peñafiel site in 947, as a frontier outpost in defense against the Arabs. A castle was built in 1013 by Sancho Garcia to protect the land. Several other members of the Spanish nobility added to the castle including Juan Manuel and Pedro Girón. Blanche I, Queen of Navarre gave birth to the Charles, Prince of Viana in the keep of Peñafiel in 1421.