Cameroon is triangular in shape. A coastal strip 10 to 50 mi (16–80 km) wide in the southwest is covered with swamps and dense tropical rain forests; it has one of the wettest climates in the world, with an average annual rainfall of 152 in. (386 cm) on the coast. Near the coast are volcanic peaks, dominated by Mt. Cameroon (13,354 ft/4,070 m), the highest point in the country. Beyond the coastal marshes and plains, the land rises to a densely forested plateau c.1,000 ft (300 m) above sea level. The interior of the country is a plateau c.2,500 to 4,000 ft (760–1,220 m) high, where forests give way to savanna. This plateau forms a barrier between the agricultural south and the pastoral north. The extreme northern regions, near Lake Chad, are dry thornbush lands. Among the many rivers that drain Cameroon are the Bénoué, the Wuori, the Sanaga, and the Nyong.
The country consists of the former French Cameroons and the southern portion of the former British Cameroons. The French, or eastern, section constitutes four fifths of the country and supports the bulk of the population. With more than 200 ethnic groups, Cameroon has one of the most diverse populations in Africa. Bantu-speaking peoples, such as the Douala, predominate along the southern coast and in the forested areas. In the highlands are the Bamiléké. Important northern groups include the Fulani and the Kirdi. French and English are the official languages, but there are also 24 major African language groups in the country. About 40% of the people follow traditional beliefs, while another 40% are Christian and about 20% are Muslim; Islam is the dominant religion of the northern regions.