Sub-Saharan Africa is comprised of four sub-regions: West Africa, Central Africa, East Africa, and Southern Africa. The land is mostly high plateaus with escarpments along the edges, and lowlands bordering the coasts. Notable landforms include the Great Rift Valley, which stretches over 4,000 miles from Asia to Africa, and contains lakes and the beginnings of major river systems. Climate varies from tropical rainforest along the equator to savannah, steppe, and desert farther south, and is influenced by elevation and proximity to the coast.
