The African Great Lakes

The African Great Lakes are the chain of inland seas that fill the trenches of the Great Rift Valley in east-central Africa, and the region takes its name from them: Victoria, the largest tropical lake in the world; Tanganyika, the second deepest and second oldest anywhere; Malawi, Kivu, Albert, Edward, Turkana. Which countries belong depends on who is asking. Burundi, the Democratic Republic of the Congo, Kenya, Rwanda, Tanzania, and Uganda make up the usual core, while Malawi, Zambia, and Mozambique are sometimes folded in on the strength of Lake Malawi. Diplomats use the phrase for a security theater as much as a landscape, which is why its boundary keeps moving.

The lakes sit in two arms of a continental tear. The Western Rift holds the deep, narrow, tectonic lakes, Tanganyika plunges 1,470 meters, deeper than any lake but Baikal, while shallow Victoria rests in a sag between the arms. The Rwenzori range, the fabled Mountains of the Moon, carries equatorial glaciers to Margherita Peak at 5,109 meters, and volcanoes such as Nyiragongo brood over the city of Goma with a lake of molten lava. The lakes feed the White Nile and hold hundreds of cichlid fish species found nowhere else, a textbook case of evolutionary radiation. Volcanic soils and dependable rain make the highlands some of the most intensively farmed land in Africa.

Roughly 318 million people live in the six core states, and the highland districts of Rwanda and Burundi are among the most crowded rural places on earth. That density is bound up with the region's tragedy: land pressure, the colonial hardening of Hutu and Tutsi identity, and cold-war weaponry all fed the 1994 genocide in Rwanda, whose aftershocks pulled Congo into wars that killed millions and have never fully ended in the eastern provinces. The same region posts some of Africa's fastest health gains, sustains a booming Kampala and Nairobi, and earns hard currency from gorillas, the Serengeti, and the lakes. Lake Victoria alone supports around 40 million people on its shores.