Site of fourth-century Christian monasticism, known also as Nitrian Valley and Desert of Scete. A shallow desert valley about 50 miles south of Alexandria, it extends diagonally across the NE tip of the Libyan desert for some thirty miles. The name derives from “natron,” the sodium carbonate found in its numerous lakes. The founder of its monastic settlements was reputed to be Amun (c.320), one of the Tall Brothers. The colony of hermits, living in lauras (i.e., clusters of windowless cells), numbered about 5,000 in the time of Macarius the Egyptian. According to Cassian, there were four churches, each with a presbyter. The colony became a center of learning; there Origenism* flourished, the Apothegmata Patrum began to be recorded, and* wrote. Barbarian attacks in the fifth century brought it low, but four ninth-century Coptic monasteries remain.