Alquézar is crowned by this large castle-monastery. Originally built as an alcázar (fortress) by the Arabs in the 9th century, it was subsequently conquered and replaced by an Augustinian monastery in 1099. Remnants are still visible. The columns within its delicate cloister are crowned by carved capitals depicting biblical scenes, and the walls are covered with spellbinding murals. On the upper level is a museum of sacred art.
