The Sơn Đoòng cave in Vietnam is one of the largest caves in the world - or even the largest depending on the metric used. Vietnam is a stunning country with so much to see and do. Vietnam is renowned for its world-class, culture, nature, food, and beaches. Two of Vietnam's famous beach destinations are Phu Quoc and Da Nang.

While not the largest, Mammoth Cave in the United States is the longest known cave system in the world and is open to the public. It has been named as a World Heritage Site since 1981 as well as an international Biosphere Reserve since 1990. There are plenty of other remarkable caves all around the United States that one can explore.

The Sheer Size of Son Doong Cave

The Son Doong cave is located near the Laos-Vietnam border and has a fast-flowing subterranean river and the largest cross-section of any cave in the world. So large is its cross-section that it is thought to be around twice the size of the world's next largest passage. It is also thought to be the largest cave in the world by volume - and it has been named by the Guinness Book of World Records as the largest since 2013.

  • Name: Hang Sơn Đoòng Can Be Translated As "Cave of the Mountain River" or "Cave of The Mountains Being Đoòng [village]"
  • Age: It is Thought To Be Between 2 and 5 Million Years Old

It is unique for the two enormous dolines (cave roof collapses) and underground rainforests and is home to the “Great Wall of Vietnam,” massive a 90m high calcite barrier.

  • Subterranean River: The Rao Thuong River Has Carved Out The Cave
  • Volume: 38.5 million cubic meters
  • Guinness Book of World Records: Listed As The Largest Cave In The World In The 2013 Edition

Related: Visiting The Stunning Maya Ritual Caves Of The Mayan Peninsula

Discovery Of The World's Largest Cave

The cave has only relatively recently been discovered and was first explored in 2009 and has only been opened to the public since 2013. It is located in the Phong Nha-Ke Bang National Park - a region that is home to some of the other largest caves in the world.

  • First Seen: 1990
  • First Explored: 2009

Its discovery began in 1990 when Mr. Ho Khanh accidentally discovered the cave entrance - he was looking for food and timber to earn a modest income. But he then forgot about it. Years later he met with the British Cave Research Association and told them what he had seen many years before. They asked him to rediscover it and he found it again in 2008.

According to Oxalis Adventure, Ho Khanh is still an integral part of every Son Doong Expedition.

But it wasn't until 2009 that Mr. Peter MacNab, a member of the British Cave Research Association (BCRA) became the first person to enter and explore the cave. The following year they announced that Hang Son Doong as the world's biggest cave with a volume of 38.5 million m3.

Today the tour group Oxalis Adventure continues to work with the British Cave Research Association.

Related: These Tours Of Kentucky's Mammoth Cave Are Worth Taking, Ranked By Difficulty

Visiting The Sơn Đoòng Cave - 4 Day Expedition

The only option to visit the Son Doong cave is on four-day expeditions with Oxalis Adventure. It is rated as hard - adventure level 6 so one much have a good level of fitness and previous trekking experience.

On this expedition, one can expect multiple river crossings (surface and underground crossings), extensive rocky terrain, and multiple technical sections. One will have to be prepared to not see the sun for this time and live in perpetual darkness - there are 3 nights of camping underground.

  • Duration: 4 Day Expedition
  • Trekking Length: 17 Kilometers (10 Miles) Of Trekking Over Very Rocky Terrain
  • Caving Length: 8 Kilometers (5 Miles) Of Caving With Rope Climbs, Scrambling, At A 90 Meter Ascent of The Wall of Vietnam
  • Camping: 3 Nights of Underground Camping

Due to its environmental sensitivity, the Vietnamese authorities limit tourists to only 1,000 per year. Each tour is normally made up of 10 tourists. Only one tour operator (Oxalis Adventure) is permitted to run the expeditions into the cave and has been doing so since the cave first opened in 2013.

  • Limit: A Limit Of Only 1,000 Tourists Per Year
  • Tour Group: Normally 10 Tourists
  • Cost: $3,000

The cost of the expedition is $3,000. This includes a 10% tax and a $660 environmental service fee.

Also, included are 22 porters for the group, five safety assistants, one international tour guide, a cave expert, two cooks, and a forest ranger.

Oxalis Adventure also offers a range of other tours to other Vietnamese caves as well as many other attractions in the region with a full range of packages.

If one is unable to tour this gigantic cave, then one can still have a virtual tour with National Geographic's online tool.

Next: This Is Why Visiting The Cave Of Winds Mountain Park In Colorado Is So Otherworldly