Mount Nyiragongo holds a lake of molten lava in its summit crater, and it has never permanently cooled. It is the largest and most persistent lava lake on Earth, churning and glowing more than a kilometre below the rim you stand on. The volcano rises 3,470 metres over the East African Rift inside Virunga National Park, in eastern Congo. The lake exists because of what the lava is made of: so low in silica that it stays runny where most lava crawls. That is also why the mountain kills. Twice in living memory a crater wall has cracked and the whole lake has drained out in under an hour — in 2002 it ran through the streets of Goma, the city of two million at its foot. Each time the crater slowly fills again, and each time people move back.
Reaching the lava takes a full day on foot. Rangers lead the climb out of equatorial rainforest, across fields of black hardened lava, and up steep slopes of loose ash — five or six hours of steady work, demanding rather than technical. You sleep in simple A-frame cabins right on the crater rim, in bitter cold at 3,470 metres. After dark the reward arrives: the crater floor, dull grey by day, pulses orange-red, gas clouds shimmer in the light, and the lake hisses and cracks far below. People stand and watch it for hours before crawling into a cabin a few metres from the drop. At dawn a sea of cloud lies below and the chain of neighbouring Virunga cones catches the first sun. For now none of this is possible. After the M23 armed group seized Goma in early 2025, Virunga National Park closed and the trek stopped.