Hang Son Doong – Son Trach in Bo Trach district, Quang Binh province, is the largest natural caves in the world.
The cave is located in Vietnam, Phong Nha-Ke Bang near the border of Laos.

Limestone mountains of the Vietnam-Laos border have many caves, such as the Phong Nha that has been known for long.
Son Doong cave was discovered in 1991 when a local called Ho Khanh, stumbled up on it when trying to avoid the rain.

In the 22nd of April 2009, was announced that Son Doong cave was actually the world’s largest.
In January 2010, explorers returned to Son Doong to learn more about the cave system.

Hang Son Doong was formed about 2-5 million years ago, when river water flew through the limestone. Water erosion created a giant tunnel under the mountains. The ceiling collapsed forming holes.
Hang Son Doong has a width of 200 meters, 150 meters in height and at least 6.5 km long. The length can still be bigger, but due to technical limitations, the explorer can not determine how long the cave might actually be.

With such dimensions, Son Doong cave has passed Deer Cave in Gunung Mulu National Park of Malaysia (with a height of 100 m, width 90 m, length 2 km) to occupy the title of the world’s largest natural Cave.

By: Haikaka National Geographic