The new discovery was declared after an exploration carried out by a joint team from the British Caving Research Association, Hanoi Natural Sciences University and the park’s administrators from March 16 to April 25.

Three most noteworthy caves are May Cave with 1,100 meters in length and 200 meters in depth, Lan Cave with 1,230 meters in length, and Vuc Moi Cave with 213 meters in depth. A Ky, a 1,260-meter-wide cave east of Road 20, is noted for a long stream that begins in neighboring Laos running through the cave.

To the west of Road 20, Vong Phu Cave is formed from limestone and impresses with 840 meters in length and 146 meters in depth. The most striking one that must be mentioned is Vuc The, which is formed with nine different levels and is 207 meters deep.

Some others have special geographical characters such as Thach Sinh, Khe Dung, En, and Bang Cave. They are sinkholes by nature, and Bang Cave has 662 meters in length can contain a large volume of water in the rainy season.

The newly-explored 39 caves were carefully measured, charted and photographed, providing new and precise figures to the administrators of Phong Nha- Ke Bang National Park.

The Phong Nha-Ke Bang National Park won UNESCO’s recognition as a heritage site in 2003 thanks to its 300 different caves and grottos which date back some 400 million years.

Son Doong, one of the most renowned caves in the park, was discovered by a local man named Ho Khanh, but had not gained international recognition until the British Cave Research Association explored it in 2009 with Khanh’s help. The cave, which is 150 meters high and 200 meters wide, was opened to tourists last year.