The entrance to Hang Sơn Đoòng was found in 1991 by a local man named Hồ Khanh, while searching for agarwood, a … See more

Formed in Carboniferous/Permian limestone, the main Sơn Đoòng cave passage is the largest known cave passage in the world by volume – 3.84×10 m (1.36×10 cu ft), according to BCRA expedition l… See more

In early August 2013, the first tourist group explored the cave on a guided tour at a cost of US$3,000 each. Permits are required to access the cave and are made available on a limited basis, from January to August. After August… See more

Plans were considered to build a cable car through the cave. The proposed system would be 10.5 km (6.5 mi) long, and cost between US$112 and $211 million. However, the plans were opposed by environment… See more