Hang Sơn Đoòng
| Sơn Đoòng cave | |
|---|---|
| Hang Sơn Đoòng | |
| Location | Quảng Bình 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: [haːŋ1 ʂɤːn1 ɗɔ̤ŋ2]), in Phong Nha-Kẻ Bàng National Park, Bố Trạch District, Quảng Bình 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.