Castillo Alcalans is a medieval fortress located in Monserrat, Valencia, constructed during the 11th-century Valencian taifa period to control the valley bearing its name and the Muslim villages, or alquerías, within the territory. The castle was captured by El Cid in 1093 before falling under Almoravide control, becoming the site of a significant 1129 battle in which the Almoravides suffered defeat. The fortress represents an important phase of medieval Iberian military strategy, controlling strategic passages through inland Castellón. Today only the ruins of its walls and foundations of various towers remain visible, yet these remnants bear witness to centuries of Iberian reconquest conflicts. Officially classified as a cultural property of interest with ministerial registration, the site preserves evidence of both Islamic and Christian medieval period construction techniques.
