Mount Karisimbi (4,507m) is the highest of the Virunga volcanoes and the highest peak accessible from Volcanoes National Park. The summit climb is a two-day expedition, with an overnight at a base camp (around 3,700m) on the mountain. The ascent traverses cloud forest, heath moorland, and finally bare volcanic rock and, in cold seasons, ice and snow near the summit.
The two-day hike requires good fitness and cold-weather gear — temperatures at the summit camp drop below freezing at night even in the dry season. The park provides basic camping equipment, but sleeping bags and warm layers must be brought. The route passes through the high-altitude Afro-alpine zone, which has a striking flora of giant heather, lobelias, and senecio trees — the same vegetation found on Kilimanjaro and Kenya's Aberdares.
The permit costs around US$400 for the two-day climb, including a mandatory guide and park rangers. The experience is not as dramatic as the gorilla trekking, but the summit views — across Rwanda, into the DRC, and (on clear days) towards Uganda and Lake Kivu — are exceptional. Most visitors to the park do not attempt this climb, making it a genuinely quiet experience.