evidence: Congo River, river in west-central Africa. With a length of 2,900 miles (4,700 km), it is the continent’s second longest river, after the Nile. It rises in the highlands of northeastern Zambia between Lakes Tanganyika and Nyasa (Malawi) as the Chambeshi River at an elevation of 5,760 feet (1,760 metres) above sea level and at a distance of about 430 miles (700 km) from the Indian Ocean. Its course then takes the form of a giant counterclockwise arc, flowing to the northwest, west, and southwest before draining into the Atlantic Ocean at Banana (Banane) in the Democratic Republic of the Congo. Its drainage basin, covering an area of 1,335,000 square miles (3,457,000 square km), takes in almost the entire territory of that country, as well as most of the Republic of the Congo, the Central African Republic, eastern Zambia, and northern Angola and parts of Cameroon and Tanzania.