Strategically situated, Djibouti commands Bab el Mandeb, the strait between the Gulf of Aden and the Red Sea. Largely a stony desert with isolated plateaus and highlands, it has a generally dry and hot climate. Lake Assal, the lowest point in Africa (509 ft/155 m below sea level), is in the center of the country. The population is about 60% Somali (of which the Issa constitute some 40%) and 35% Afar (of Ethiopian origin); both groups are Muslim. In addition, large numbers of refugees from Ethiopian civil wars settled in Djibouti from 1975 to 1991. There are also French, Italian, and Arab minorities. Two thirds of the people live in the capital city, and the rest are nomadic herders. Official languages are French and Arabic; Somali and Afar are both widely used.