Castillo de Castilnuevo dominates the landscape above a Guadalajara valley, with construction spanning multiple centuries from the 8th to 12th centuries. Built initially in mudejar style by Arab builders, the fortress was later enhanced by Christian owners, featuring a trapezoidal outline adapted to its hilltop setting, a large tower keep, and square corner towers reinforced by additional turrets. Historical documents show that King Alfonso I el Batallador signed numerous documents at the site while directing his conquest of Molina in 1128. Over time it evolved from a military fortress into a noble strong house, serving as a retreat for figures including Doña Blanca de Navarra. Declared a National Monument in 1931, the castle represents an important example of medieval military and residential architecture.
