Guinea is divided into four main regions: Maritime Guinea, also known as Lower Guinea or the Basse-Coté lowlands, populated mainly by the Susu ethnic group; the cooler, mountainous Fouta Djallon that run roughly north–south through the middle of the country, populated by Fulas; the Sahelian Haute-Guinea to the northeast, populated by Malinké; and the forested jungle regions in the southeast, with several ethnic groups. Guinea's mountains are the source for the Niger, the Gambia, and Senegal Rivers, as well as the numerous rivers flowing to the sea on the west side of the range in Sierra Leone and Ivory Coast.