The Alcázar de los Reyes Cristianos (Spanish for "Alcázar of the Christian Monarchs"), also known as the Alcázar of Córdoba, is a medieval Alcázar located in Córdoba, Spain next to the Guadalquivir River and near the Grand Mosque. The Alcázar takes its name from the Arabic word القصر (Al-Qasr, meaning "the Palace"). The fortress served as one of the primary residences of Isabella I of Castile and Ferdinand II of Aragon.