Lake Tanganyika is an African Great Lake. It is estimated to be the second largest freshwater lake in the world by volume, and the second deepest, after Lake Baikal in Siberia; it is also the world's longest freshwater lake. The lake is divided among four countries – Burundi, Democratic Republic of the Congo (DRC), Tanzania and Zambia, with the DRC (45%) and Tanzania (41%) possessing the majority of the lake. The water flows into the Congo River system and ultimately into the Atlantic Ocean.
The lake is situated within the Albertine Rift, the western branch of the geographic feature known as the East African Rift, and is confined by the mountainous walls of the valley. It is the largest rift lake in Africa and the second largest lake by volume in the world. It is the deepest lake in Africa and holds the greatest volume of fresh water. It extends for 676 km (420 mi) in a general north-south direction and averages 50 km (31 mi) in width. The lake covers 32,900 km2 (12,700 sq mi), with a shoreline of 1,828 km (1,136 mi) and a mean depth of 570 m (1,870 ft) and a maximum depth of 1,470 m (4,820 ft) (in the northern basin) it holds an estimated 18,900 cubic kilometres (4,500 cu mi).