Horn of Africa covered the Simien and Bale Mountains but melted at the beginning of the Holocene. The mountains descend in a huge escarpment to the Red Sea and more steadily to the Indian Ocean. Socotra is a small island in the Indian Ocean off the coast of Somalia. Its size is 3,600 km (1,390 sq mi) and it is a territory of Yemen. The lowlands of the Horn are generally arid in spite of their proximity to the equator. This is because the winds of the tropical monsoons that give seasonal rains to the Sahel and the Sudan blow from the west.
Horn of Africa Bantu groups also speak variants of the Niger-Congo Swahili and Mushunguli languages. The countries of the Horn of Africa have been the birthplace of many ancient, as well as modern, cultural achievements in several fields including agriculture, architecture, art, cuisine, education, literature, music, technology and theology. Ethiopian agriculture established the earliest known use of the seed grass teff ("Poa abyssinica") between 4000–1000 BCE. Teff is used to make the flatbread injera/taita. Coffee also originated in Ethiopia and has since spread to become a worldwide beverage. Ethiopian art is renowned for the ancient tradition of Ethiopian Orthodox Christian iconography stretching back