What is the largest cave in the world?
Quick answer
Hang Sơn Đoòng (Son Doong) in Vietnam’s Phong Nha-Kẻ Bàng National Park has the largest known cave passage in the world by volume. Parts of its main passage are more than 200 m tall and 150 m wide, big enough to fit a 40-story building. It even has its own jungle and weather, including clouds.
Key facts
- Location
- Phong Nha-Kẻ Bàng National Park, Quảng Bình, Vietnam
- Length
- More than 9 km (main passage)
- Volume
- About 38.5 million m³
- Explored
- 2009, by the British Cave Research Association
Discovery
A local man, Hồ Khanh, found the cave’s entrance around 1990 while sheltering from a storm in the jungle, hearing a roaring river and feeling wind from inside. He later couldn’t find it again. In 2008 he rediscovered it, and in 2009 a team from the British Cave Research Association, led by Howard and Deb Limbert, explored it and revealed its enormous size.
The name means roughly “mountain river cave.”
Jungles and clouds underground
| Feature | What it is |
|---|---|
| Dolines | Two places where the roof collapsed, letting sunlight in |
| Underground jungle | Trees up to about 30 m tall grow beneath the openings |
| Cave pearls | Rare, round calcite formations, some as big as baseballs |
| The “Great Wall of Vietnam” | A 90 m calcite wall near the exit |
| Clouds | Temperature differences form mist inside |
Largest by what measure?
| Record | Cave |
|---|---|
| Largest passage by volume | Son Doong, Vietnam |
| Largest single chamber by volume | Miao Room, Gebihe Cave, China |
| Longest cave system | Mammoth Cave, Kentucky, USA, over 680 km mapped |
| Deepest cave | Veryovkina Cave, Georgia, over 2,200 m |
Visiting Son Doong
Access is strictly limited to protect the cave. Licensed operator Oxalis Adventure runs multi-day expeditions for a small number of visitors each year, costing several thousand dollars. Trips involve jungle trekking, river crossings and camping inside the cave, and require good fitness.
How caves like this form
Son Doong formed over millions of years as a river dissolved soft limestone along a weak fault line. The same process of rock dissolving is explained in what weathering is. Limestone also forms dramatic landscapes above ground; see the white terraces of Pamukkale.
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