Virunga (vērŏngˈgä) [key], volcanic range of mountains, E Congo, N Rwanda, and SW Uganda, central Africa, NE of Lake Kivu. It extends along the eastern rim of the Great Rift Valley and separates the basins of the Nile and Congo rivers. Karisimbi (14,786 ft/4,507 m) is the highest peak, and the range includes the active volcanoes Nyiragongo and Nyamuragira (Nyamulagira). Much of the range is now administered as national park land. It is also called the Mfumbiro range.