Horn of Africa Horn of Africa The Horn of Africa (, , , , ) (shortened to HOA; alternatively Somali Peninsula) is a peninsula in Northeast Africa. It juts hundreds of kilometers into the Arabian Sea and lies along the southern side of the Gulf of Aden. The area is the easternmost projection of the African continent. Referred to in ancient and medieval times as "Land of the Berbers" and "Habesha", the Horn of Africa denotes the region containing the countries of Djibouti, Eritrea, Ethiopia, and Somalia. It covers approximately 2,000,000 km (770,000 sq mi) and is inhabited by roughly 115 million people
German horn excessive. Although the French firm Jérôme Thibouville-Lamy in about 1928 introduced a piston-valved double-horn with ascending third valve, designed in collaboration with the horn player Louis Vuillermoz, the double horn has continued to be identified mainly as a German horn. The double horn essentially combines two instruments into a single frame: one horn in F, and a second, higher horn keyed in B. Like the single horn it has three valves, but each has a double set of tubing, the first tuned in F and a shorter set in B. By depressing a fourth valve (usually operated by the thumb),