Language En
Son Doong Exploration

Son Doong Exploration

Son Doong Exploration

From an early age, local man Ho Khanh used to spend weeks on end trekking and maneuvering his way through the jungles of the Phong Nha-Ke Bang National Park, searching for food and timber to earn a living.

In 1990, while out on a hunting mission, Ho Khanh stumbled upon an opening in a limestone cliff and moved forward to investigate. As he approached he noticed clouds billowing out of the entrance, and could hear the sounds of a river raging from somewhere inside the cave.

When he could also feel a strong wind blowing out from the cave, he decided to move on without further inspection. By the time he had returned to his home a few days later, he had forgotten its exact location and thought no more of it.

At the same time two members of the British Cave Research Association (BCRA), Howard and Deb Limbert, were basing themselves in Phong Nha to conduct exploratory cave expeditions in the area. While chatting with Ho Khanh one day, he mentioned to the caving experts that he had found a cave with clouds and a river inside. Howard and Deb were intrigued instantaneously and urged Ho Khanh to try and rediscover the cave. After many failed attempts, they began to think this elusive cavern might remain lost in the jungle forever.

In 2008, while out on another food gathering trip, Ho Khanh found the mysterious opening again and studiously took note of the path on how to get there. In 2009 he led Howard, Deb and a team of professionals back to the cave for the first expedition to enter what would later become known as Hang Son Doong, or the ‘Mountain River Cave’.

Ho Khanh is still an integral part of every Son Doong Expedition, if he is not guiding groups, he is back in town organizing porters and leading our safety response group.


How big is Son Doong Cave?

The volume of Son Doong Cave is 38.8 cubic million with 9km in length in present. The average passage size for Hang Son Doong is 67.2m; with the average height of the cave is 200m and the average width is about 150m. Hang Son Doong is big enough to fit an entire block of New York City with 40-storey skyscrapers. Stalagmites up to 80m high have also been surveyed, the tallest ever encountered.


How was Hang Son Doong formed?

Son Doong Cave has the largest cave passage in the world located in Phong Nha – Ke Bang National Park, Quang Binh, Vietnam. While Phong Nha – Ke Bang National Park is one of the oldest system of limestone mountain in Asia with around 400 million years old, Hang Son Doong was only explored in 2009 and is less than 3 million years old.

Two large rivers, Khe Ry and Rao Thuong, joined together to form Son Doong Cave  millions of years ago, creating a huge passage beneath the limestone mountains. Breakages in the cave ceiling are corroded and subsided, forming large holes – called dolines. This enables the unusual formations like Phytokarst to develop, and also plants and trees to grow inside the cave.


Who discovered Son Doong Cave?

A local man named Ho Khanh discovered the cave back in 1990s, and in 2009 he led a team of British cavers (members of British Cave Research Association) to the cave.

In 2005, the cave experts met up with Mr Ho Khanh who knew a number of caves in the area. He had a vague memory of a cave he had seen about 20 years ago when foraging in the jungle. In 2007 he attempted to take the team there, but could not locate the cave. In 2008 he went back by himself to the jungle, and searched until he found the entrance again.

Back in 1994, members of the British Cave Research Association explored Hang En and Hang Thung.  A large river passes through Hang En, disappears underground and reappears in Hang Thung. In between was a gap of several kilometres. Hang En and Hang Thung are both large river caves, so the team expected there to be a significant cave in between.  Every expedition they asked the local jungle men if they knew any entrances in the area which might lead to the cave, but no-one did.

In 2009 a team of British cavers went to the area with Mr Khanh to explore a number of entrances. The first one they saw turned out to be Son Doong. Not only was it a significant cave, but probably the most significant cave in Vietnam and perhaps the world. After surveying (measuring and mapping the cave), they discovered its full dimensions. After further research they determined Son Doong to be the largest cave passage in the world. Other spectacular features make Son Doong an amazing place; underground rivers, huge formations, dolines or skylights, ancient fossils, unique species of fish and insects, plants and trees inside the cave.

Exploration and surveying of the cave was completed in 2010, and National Geographic Magazine and Film Channel visited the cave. They produced a documentary and magazine article in 2011. This drew the attention of travellers to Vietnam, who started to visit Quang Binh and Phong Nha. Many documentary films have since been made from around the world.


Geology of Son Doong Cave

Son Doong Cave has the largest cave passage in the world, and was only explored in 2009.Two large rivers, Khe Ry and Rao Thuong, join together to form Son Doong Cave. The cave follows a large fault line that's 100m wide, which contributes to the huge size of the passages.

The Phong Nha Ke Bang limestone is around 400 million years old, but Hang Son Doong is less than 3 million years old.

The cave has two skylights, which allow daylight into the cave. This enables the unusual formations like Phytokarst to develop, and also plants and trees to grow inside the cave. Spectacular sunbeams are often seen at the first doline. Mist and clouds usually form in the large cave passages and rise up to the dolines.



Son Doong Cave

Son Doong Cave

Son Doong Cave is located in the heart of the Phong Nha Ke Bang National Park in Quang Binh province of Central Vietnam. Only recently explored in 2009-2010 by the British Cave Research Association, Son Doong Cave has only been open to the public since 2013. All research and tourist expeditions have thus far have been organized and led by local adventure tour company Oxalis, in partnership with British Cave Research Association and with the permission of the government of Vietnam.

Hang En Cave

Hang En Cave

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.