An irregular chain of mountains, hills, and plateaus known as the Cameroon range extends from Mount Cameroon on the coast—Cameroon's highest point at —almost to Lake Chad at Cameroon's northern border at 13°05'N. This region has a mild climate, particularly on the Western High Plateau, although rainfall is high. Its soils are among Cameroon's most fertile, especially around volcanic Mount Cameroon. Volcanism here has created crater lakes. On 21 August 1986, one of these, Lake Nyos, belched carbon dioxide and killed between 1,700 and 2,000 people. This area has been delineated by the World Wildlife Fund as the Cameroonian Highlands forests ecoregion.