Which active volcano in the Democratic Republic of the Congo has a persistent lava lake?

Mount Nyiragongo is the active volcano in the Democratic Republic of the Congo known for its persistent lava lake. It rises in the Virunga Mountains of North Kivu Province, about 12 kilometres north of Goma and near the Rwandan border.

Nyiragongo is a stratovolcano formed by volcanic activity along the Albertine Rift, the western branch of the East African Rift. Its main crater is roughly two kilometres wide and has frequently contained a churning lake of molten lava. Scientists confirmed the lava lake's existence in 1948, although volcanic activity had been observed earlier.

The lake is not permanently stable: its depth and level change, and major eruptions can drain it rapidly. In January 1977, the crater lake emptied in less than an hour after fractures opened in the crater walls. In 2002, lava flows reached Goma, causing widespread destruction. A major flank eruption also occurred in May 2021.

Mount Meru, Mount Cameroon, and Mount Kilimanjaro are African volcanoes, but none is the canonical answer to this particular lava-lake question.