Into the Dark: Exploring the Lava Caves of Uganda and Rwanda

How lava caves form in the Virunga volcanoes

The Virunga caves are lava tubes: hollow channels left behind when the surface of a lava flow cooled into a hard roof while molten rock kept flowing underneath, then drained away. Geologists also call them lava caves or volcanic caves, and local villagers in Kisoro call them urutare, meaning “rock”.

The Virunga chain stretches about 80 km from the Cyanika border to Lake Kivu, with eight volcanoes along the Rwanda–Uganda–DRC border. The name comes from the Kinyarwanda word ibirunga, meaning “volcanoes”. Geologically they sit on the western branch of the East African Rift. On the Uganda–Rwanda border stand three extinct stratovolcanoes: Muhabura (4,127 m), Sabyinyo (3,611 m, the oldest) and Gahinga (3,470 m), which you can read about in our Mgahinga guide.

What you will see underground

• Half-dome ceilingsShaped by the flowing lava, often in passages 10 m wide and 5–8 m high.
• Pahoehoe and aa lavaSmooth, ropy flows on the floor, switching to rough, clinker-like rock and back again.
• Collapse entrancesWhere the roof has caved in, round pits 10–20 m across open in the fields.
• Hanging tree rootsIn shallow tubes, where the ceiling sits just below the farmland.
• Magma columnsSolidified columns and red-coloured lava flows in side passages.

The 2022 expedition noticed that most Ugandan tubes sit between 2,100 m and 2,300 m. Their theory: at this altitude the slope angle is just right for lava tubes to form. The tubes all run roughly north–south, following the downhill path of the ancient flows. Larger lava fields are rare elsewhere in Uganda, so the Virunga foothills are likely the country’s main lava cave zone.

The lava caves of Rwanda and Uganda

Rwanda has the developed show cave and the long systems; Uganda has the raw, barely mapped frontier. Visit Rwanda counts 52 caves in the Northern Province with 15.2 km of passages. In Uganda, a team led by Joerg Dreybrodt surveyed 23 caves totalling about 3 km in seven days in December 2022, in a 16 km by 8 km zone between the Cyanika border and Kisoro town. Before that, Uganda’s longest known cave was Garama at 324 m.

Ugandan lengths are from the 2022 expedition report; Rwandan lengths come from the published surveys linked in this guide. The “suggested level” is our reading of each cave’s description, and your local guide confirms it before you go.

Musanze Cave: the easy way in

Musanze Cave is the easy entry point. It runs about 2 km, has 31 entrances (mostly roof collapses) and a main portal described as “the size of a cathedral”, with light shafts and a sizeable bat colony. It opened to the public in 2013 and is visited only on guided tours of about two and a half hours, booked through the Rwanda Development Board or a tour operator (Visit Rwanda, Showcaves.com). It sits close to Volcanoes National Park, so it pairs easily with a gorilla trek.

For serious cavers, the region holds much more. Swiss-German expeditions led by Michael Laumanns between 2003 and 2007 mapped dozens of tubes, some several kilometres long, with passages 10 m wide and 8 m high running for kilometres. Ubuvumo Nyabikuri-Ruri (3,384 m, surveyed in 2004) is the longest single cave found in Rwanda.

Kisoro’s hidden tubes

Around Kisoro, in far south-west Uganda, village caves sit in fields between the Cyanika border and Kisoro town. Urutare rwa Sooko (1,025 m) is the longest, with an 8 m wide portal, fragments of old pottery at the entrance and red pahoehoe lava inside. Urutare rwa Ruhengo is run as a visitor experience by Amajambere Iwacu Community Camp. Urutare rwa Kararama has an entrance hole under a metre wide in a field, then crawls beneath hanging roots. Garama Cave lies inside Mgahinga Gorilla National Park and is visited on the Batwa Trail (see Culture and history).

Resting from the caves? The same hills around Kisoro are good riding country; see our cycling guide for Lake Mutanda and Kisoro.

Where the surveyed caves are

Schematic map drawn from the survey coordinates of the 7 caves whose positions are confirmed. Sooko and Cugyi lie only about 200 m apart, so their pins are spread slightly. The other five caves are not shown because their coordinates are still being confirmed. This map is not for navigation; your guide takes you to each entrance.

Wildlife underground: bats and cave invertebrates

These shallow tubes are surprisingly full of life, and almost none of it has been studied. Lava cave biology is a young science, pioneered in Hawaii, the Canary Islands and the Azores; Sub-Saharan Africa has seen little beyond bat surveys. Roots dangling through the ceiling and debris washed in by rainy-season streams feed a rich food web. The 2022 team logged every sighting in the Cave Life App, but took no samples because a fauna export permit had not been granted. That means species new to science may be waiting down there.

If you go, record what you see in the Cave Life App and share photos with local partners, such as Rwanda’s Center of Excellence in Biodiversity. Every observation helps map this unknown ecosystem. For the wider picture of wildlife above ground, see our guide to Uganda’s national parks.

Culture and history: refuges, kings and memory

These caves are not just geology; people have used them for more than a thousand years, as homes, hiding places and sacred sites.

• Ancient occupation. Archaeologists excavated Musanze caves in 1983 and again in 2006–07. One radiocarbon date puts the earliest occupation at around AD 875 (Showcaves.com).
• The Batwa’s Garama Cave. Before Mgahinga became a national park in the early 1990s, the forest was home to the Batwa people. Garama served as a hiding place and ceremonial site, and is described as where the Batwa king held court. Today Batwa guides lead visitors there on the Batwa Trail, which also covers honey gathering, hunting and fire-making. Our Mgahinga guide explains the Batwa Trail in full.
• Everyday traces. The entrance of Urutare rwa Sooko is scattered with broken pottery.
• Painful history. Musanze Cave was a wartime shelter for centuries and a massacre site during the 1994 genocide against the Tutsi; some Rwandan caves still contain human remains (Visit Rwanda). In Uganda, the 2022 team found human bones and intact skulls near the entrance of Kararama Cave.

The local community is part of the adventure. Villagers in Kisoro guided the 2022 team to entrances, often having explored only by mobile phone light. Bringing spare headlamps and inviting them in turned a survey into a shared discovery. Our guide to responsible and sustainable safari travel explains how to choose trips that leave money and respect in the places you visit.

Sample 10-day lava cave itinerary: Kigali to Kisoro

A cross-border lava cave trip can be done in 10 days: a few days around Musanze in Rwanda, then over the Cyanika border to Kisoro, Uganda. This is a suggested shape, and we adjust it to your dates, group and experience.

1. Step 1KigaliFly into Kigali and drive 2–3 hours on good tarmac to Musanze.
2. Step 2MusanzeSpend 2–3 days on the guided Musanze Cave tour and, with permits, longer tubes nearby.
3. Step 3Cyanika borderCross at Cyanika into Uganda and base near the main gate of Mgahinga Gorilla National Park. Our guide to the Cyanika border crossing explains how it works.
4. Step 4Kisoro cavesSpend 4–6 days exploring village caves around Kisoro with a local guide, plus Garama on the Batwa Trail.
5. Step 5Gorillas or a volcano climbAdd a gorilla trek or a climb of Muhabura, Sabyinyo or Gahinga to round it off. See gorilla trekking in Uganda and in Rwanda.

Want this route with both gorilla permits, or one country only? Read how to combine Uganda and Rwanda gorilla trekking, compare Uganda and Rwanda, or browse our ready-made itineraries.

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What to pack for a lava cave

• Helmet with two independent light sources plus spares
• Knee and elbow pads for crawls over sharp aa lava
• Tough gloves and sturdy boots
• FFP2/N95 masks for bat roosts
• Short ladder or rope if you want to reach upper passages (several in Sooko were left unmapped for lack of one)
• Spare headlamps to lend local guides
• First aid kit and water

Your gorilla trek and the rest of the trip need their own kit; see the East Africa safari packing list.

Safety and responsible caving

Lava caves in Uganda and Rwanda: frequently asked questions

Keep reading

On a rest day near Kisoro? See our cycling safari guide for Lake Mutanda.

New to safaris? Start with What Is a Safari? Types of Safari and How to Choose.