Son Doong Cave
Tu Lan Cave System is comprised of over 10 caves in all, some of which were originally discovered and explored in 1992, and some of which were just found in the past couple years.
The karst in the Quang Binh province of central Vietnam is notable for the extensive series of very large cave passages that drain through the blocks of limestone. Many of the caves are part of the Hang Phong Nha system. In March 2012, the British-Vietnamese Caving Expedition was fortunate to be able to explore Hang Va.
Hang En Cave (Hang Én) is the world’s 3rd largest cave, succeeded only by Deer Cave in Malaysia and Hang Son Doong, also located here in the Cave Kingdom of Vietnam, Phong Nha-Ke Bang National Park.