Monreale (mōnrāäˈlā) [key], town (1991 pop. 26,256), NW Sicily, Italy, near Palermo. An agricultural market and tourist center, it commands a magnificent view of the fertile Conca d'Oro plain. A famous cathedral, one of the masterpieces of Norman-Sicilian architecture, was begun there (1174) by William II of Sicily. The cathedral has fine copper doors by Bonanno Pisano; its interior is decorated with exceptional Byzantine mosaics. Nearby is a lovely cloister with about 200 twin columns and an Arab fountain formerly used as a lavabo.