Hang Sơn Đoòng
| Sơn Đoòng Cave | |
|---|---|
| Hang Sơn Đoòng | |
| Location | Quảng Trị province, Vietnam |
| Coordinates | 17°27′25″N 106°17′15″E / 17.45694°N 106.28750°E |
| Depth | max. 150 metres (490 ft) |
| Length | approx. 9 kilometres (5.6 mi) |
| Discovery | 1991 by Hồ Khanh |
| Geology | Permo-Carboniferous limestone |
| Entrances | 2 |
| Hazards | Underground river |
| Cave survey | 2009, British/Vietnamese |
| Website | https://sondoongcave.info |
Sơn Đoòng Cave (Vietnamese: hang Sơn Đoòng, IPA: [haːŋ ʂəːŋ ɗɔŋ͡m]), in Phong Nha – Kẻ Bàng National Park, Quảng Trị Province, Vietnam, is the world's largest natural cave.
Located near the Laos–Vietnam border, Hang Sơn Đoòng has an internal, fast-flowing subterranean river and the largest cross-section of any cave, worldwide, believed to be twice that of the next-largest passage. It is the largest known cave passage in the world by volume.
Its name, Hang Sơn Đoòng, is translated from Vietnamese as "cave of the mountain behind Đoòng". Đoòng is the name of a Vân Kiều village.
As a solutional cave, it was formed in soluble limestone and is believed to be between 2 and 5 million years old.