Castillo Mayor de Daroca is an 11th-century fortress perched on a hill that dominates the town of Daroca in the province of Zaragoza, Aragón. Originally constructed during the Islamic period and reformed during the 19th century (1837), the castle represents the culmination of Muslim military architecture in the region. The fortress features an oval floor plan measuring approximately 80 by 30 meters, with its most notable element being a rectangular tower constructed of mortar and stone masonry with a distinctive pointed arch. Owned and maintained by the Daroca City Council, the castle offers free public access and stands as a significant example of medieval Iberian military heritage with commanding views of the surrounding landscape.