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 to wall paintings of the 7th century CE. Somali architecture includes the Fakr ad-Din Mosque, which was built in 1269 by the Fakr ad-Din, the first Sultan of the Sultanate of Mogadishu. Ethiopia is renowned for its ancient churches, such as at the UNESCO World Heritage Site at Lalibela. The Horn has produced numerous indigenous writing systems. Among these is Ge'ez script ( ') (also known as "Ethiopic"), which has been written in for at least 2000 years. It is an abugida script that was originally developed to write the Ge'ez language. In speech communities that use it, such as