During the Muslim rule on Sicily, the island was divided into three different administrative regions: the Val di Noto in the southeast, the Val Demone in the northeast and the Val di Mazara in the west. Each zone has a noticeably different agriculture and topography and they converged near Castrogiovanni. The term val or vallo (plural valli) is probably derived from the Siculo-Arabic wilayah, meaning "province". The three valli are represented by the three-legged Trinacria symbol which appears on the flag of Sicily.