Much of Gabon, which is situated astride the equator, is drained by the Ogooué River (and its tributaries, the Ngounie and the Ivindo), which flows into the Atlantic through a long and broad estuary. The rest of the coastline comprises a narrow low-lying strip, which, south of the Ogooué's mouth, includes a series of lagoons. The interior of the country is made up of mountain ranges and high-lying plateaus. To the north of the Ogooué are the Cristal Mts. and to the south is the Chaillu Massif, which includes Mt. Iboundji (5,165 ft/1,574 m), Gabon's highest point. In the northeast is the Woleu-Ntem Plateau, which reaches c.2,500 ft (760 m), and in the southeast is the hot and arid Bateke Plateau (c.2,700 ft/820 m).
The inhabitants of Gabon belong to several ethnic groups including the Fang (who make up about one quarter of the population) in the north, the Omiéné along the coast, the Bakota in the northeast, and the Eshira in the southwest. French is the country's official language, but African languages are also spoken, and the country is seeking to increase the use of English. There are large numbers of immigrant workers from other French-speaking African nations, as well as Europeans, mainly French. The population is predominantly Christian in the cities, but most people in the countryside adhere to traditional beliefs.