Castillo de Sora crowns Monte Guarizo in the Cinco Villas region of Zaragoza province, offering expansive views from the Prepirineo to the Ebro valley. Built in the 9th century by the Banu Qasi dynasty, it became one of their pillars of power, with Musa ibn Musa attributing part of his claim to be the 'third king of Spain' to controlling this fortress. The castle features a triangular walled enclosure with square towers and a Renaissance-finished keep reinforced in 1547. Declared a Cultural Interest Asset, it remains a significant example of medieval Islamic and Aragonese military architecture.
