Nhan Dan Online - Recently, Son Doong Cave (Bo Trach District, North of Dong Hoi, Central Quang Binh Province of Vietnam) was voted one of the 20 Record-Breaking Wonders of Nature by Business Insider.

Located in Phong Nha-Ke Bang National Park, Son Doong Cave, nearly 5 km long, is the largest cave in the world.

The cave is estimated to be between 400 and 450 million years old, but it was first discovered in 2009.

Son Doong Cave is nearly 5 km long, 198 meters high, and is wide enough to have a climate system independent of the outside environment. This wonder even has its own clouds, forests and rivers. It is seen as a fictional world that has not been touched by men.

NDEL