The whole region is characterized by a remarkable degree of physical uniformity, and may be broadly described as a vast plateau of an average elevation of 3000 ft., bounded westwards by the Ethiopian and Galla highlands and northwards by an inner and an outer coast range, skirting the south side of the Gulf of Aden in its entire length from the Harrar uplands to Cape Guardafui.
Between the Harrar plateau and Cape Guardafui the coast ranges maintain a mean altitude of from 4000 to 5000 ft., and fall generally in steep escarpments down to the narrow strip of sandy lowlands skirting the Gulf of Aden.
Mefat which enters the Gulf of Aden near Balhaf.
In the region of Somaliland, now the western part of the British protectorate of that name, the Arabs established the Moslem state of Adel or Zaila, with their capital at Zaila on the Gulf of Aden.
In 1521 the then sultan Abubekr transferred the seat of government to Harrar, probably regarding Zaila as too exposed to the attacks of the Turkish and Portuguese navies then contending for the mastery of the Red Sea and Gulf of Aden.
