Phong Nha-Kẻ Bàng National Park, located in the Quang Binh province of central Vietnam, is home to many colorful caving adventures. The park is a designated UNESCO World Heritage Site made up of the oldest karst limestone rock formations in Asia. There are currently 300 known caves and grottoes, but new caves are regularly discovered.
SON DOONG CAVE
The most recent cave to be found is Son Doong cave, discovered in 2009. Son Doong is considered to be the largest cave in the world. More than 3 miles long with ceiling heights over 650 feet, Son Doong cave houses both a subterranean river and a rainforest within its depths. This cave is truly breathtaking, but space to see it is limited. Due to conservation concerns, the Quang Binh province restricts the number of annual visitors, and only one outfitter, Oxalis Adventure Tours, provides tours.