Two principal regions may be recognized in Sinai. The first region is the southern complex of high mountains, including such peaks as Mount Kātrīnā (Catherine), elevation 8,668 feet (2,642 metres); Umm Shūmar, 8,482 feet (2,585 metres); Al-Thabṭ, 7,997 feet (2,437 metres); and Mount Sinai, 7,497 feet (2,285 metres). The southern region is essentially composed of igneous rocks and is sharply incised by deep, canyonlike wadis (seasonal watercourses) that drain toward the Gulf of Suez or the Gulf of Aqaba. This gaunt mountain mass is separated from the Gulf of Suez to the west by a narrow coastal plain, but on its eastern side it rises precipitately from the Gulf of Aqaba. The second region, flanking this mass on the north and forming two-thirds of Sinai, is a great plateau sloping from heights of more than 3,000 feet (900 metres) downward to the Mediterranean.
