The Mystery at the Bottom of Son Doong Cave

 Nearly 30 years ago, 300 caves that nest in Quang Binh Province were discovered, most of them are dry or underground caves. Up to now, there has been no survey on underground rivers and underground caves. The turning point is when a group of leading diving experts came to discover Son Doong, the largest cave. It is the British Cave Expedition team led by Howard Limbert who announced the 200km long cave in Phong Nha - Ke Bang National Park. 

Vietnam is endowed with one of five most desirable tourist destinations in 2019. Sharing with the local media, Howard said the cave system here is still many, currently 25% only discovered. Each cave is separate on the surface but connected below.