The smallest country on the continent of Africa, The Gambia comprises Saint Mary's Island (site of Banjul) and, on the adjacent mainland, a narrow strip never more than 30 mi (48 km) wide; this finger of land borders both banks of the Gambia River for c.200 mi (320 km) above its mouth. The river, which rises in Guinea and flows c.600 mi (970 km) to the Atlantic, is navigable throughout The Gambia and is the main transport artery. Along The Gambia's coast are fine sand beaches; inland is the swampy river valley, whose fertile alluvial soils support rice cultivation. Peanuts, the country's chief cash crop, and some grains are raised on higher land. The climate is tropical and fairly dry.
The Gambia's population consists primarily of Muslim ethnic groups; the Malinke (Mandinka) is the largest, followed by the Fulani (Fula), Wolof, Diola (Jola), and Soninke (Serahuli). Almost a tenth of the population is Christian. English is the official language, but a number of African dialects are widely spoken. During the sowing and reaping seasons migrants from Senegal and Guinea also come to work in the country.