Is Exploring the World’s Largest Cave on Your Bucket List?

The world’s largest cave can be found in Vietnam. Designated a UNESCO World Heritage Site in 2003, the remarkable Phong Nha Ke Bang National Park contains the oldest karst mountains in Asia, formed approximately 400 million years ago. Riddled with hundreds of cave systems – many of extraordinary scale and length – and spectacular underground rivers, Phong Nha is a speleogists’ heaven on earth.

In 1990, a local man named Ho Khanh discovered Hang Son Doong cave, located in the Phong Nha Ke Bang National Park. Twenty years later, with the support of the British Cave Research Associal (BCRA) team members, this cave was explored, and considered to be the largest in the world. This discovery helped to encourage the growth of tourism, and with it, the lives of the local people have also improved. Previous to this, locals had little opportunity to earn a decent living. Their only source of income was from the treasures they claimed from the jungle.

In 2011, with the continued support from the BCRA members, Oxalis Adventures was founded. As an adventure tour operator, Oxalis was given exclusive permission to run tours in the park. Since its establishment, Oxalis has worked tirelessly to help improve life for the local people. By creating secure jobs, the locals no longer need to hunt in the jungle. They now have better housing, better education, better health, and a brighter future for their families.

The Son Doong Expedition has been listed worldwide as one of the top bucket list adventures, where you get to adventurously explore the largest cave on earth over a span of 4 days and 3 nights. Exploring, sleeping and even breathing inside the largest underground cave on the planet is a once in a lifetime experience!

How to book this tour?

The current regulation allows only 1,000 tourists per year to visit the cave, with each tour containing 10 tourists and the cost is $3,000 USD/ person. Availability is from February to the end of August.  You should be aware that this tour is rated HARD and involves moderate to hard trekking (25km/ total elevation gain 800m) on very rocky terrain; 7km of caving which includes rope climbs, rocky scrambling, and the 90m ascent of the Wall of Vietnam (technical sections with instruction, supervision and safety equipment); surface and underground river crossings; and 3 nights of camping underground.

Below is a breakdown of where your money will go:

  • 10 percent tax is already included ($660 is the environmental service fee that will be transferred to the management of the Phong Nha Ke Bang National Park.
  • The fees also go to the 22 porters, five safety assistants, one international tour guide, a cave expert, two cooks and a forest ranger who accompany every 10 people on the tour.
  • Other expenses include transportation, hotel, food and drinks, management and administration during the tour (Not including international and domestic airfares).

When booking, there are five steps you need to go through before your expedition will be secured:

  1. Online Booking – Choose a date for your expedition and fill in your booking form completely. Please be detailed and honest about your medical and fitness history.
  2. Automatic Notification Email – You will receive an automatic notification email that your booking has been received. If you receive this email, your spots are being held while your application is being reviewed.
  3. Booking Review – The technical advisory team will thoroughly review your application and contact you if further information is needed. This may take up to 5 business days.
  4. Approve Email & Payment Processing – At this step, payment will be required via a credit card payment link that will be sent to you.
  5. Booking Finalization – Once payment is received, your tour is confirmed.
  6. Pre-Departure Support and Follow-Up – If you need any information or support leading up to your tour, including planning your arrival and departure or booking extra nights, the booking office will be available to assist you.

Looking for a less expensive adventure and not so difficult?

Wild Tu Lan Cave Explorer

There are actually six different caving systems in and around Phong Nha-Ke Bang National Park and Oxalis Adventure runs tours to all of them. Whether you prefer long treks, camping in a cave, sleeping under the stars in the jungle, swimming underground in river caves, exploring huge dry caves or just taking an exploratory day trip, Oxalis Adventure Tours can provide the right amount of adventure just for you.

On our visit in 2018, we did the Wild Tu Lan Cave Explorer, a 3-day tour rated MODERATE. This exciting journey has some challenging sections, but with the help of the team, we explored six amazing caves. River caves where you can swim or raft and dry caves covered in outstanding calcite formations.

How to get there?

There are currently 5 airlines that operate out of the Dong Hoi Airport, which is the gateway to Phong Nha-Ke Bang National Park, located 50km northwest of the city.  You can find direct flights here from Hanoi and Ho Chi Minh City.

Oxalis will arrange round-trip airport transfers from Dong Hoi to Phong Nha before and after the tour.

Where to stay before and after your tour?

If doing the Son Doong Expedition with Oxalis Adventure, you’ll stay at the Son Doong Bungalow before the tour and at Chay Lap Farmstay & Resort after the tour. We recommend staying a few extra nights in Phong Nha as there’s much more to do there aside from trekking and exploring caves. There is mountain biking, kayaking, swimming, ziplining, and mud baths. We recommend taking a bike ride to the nearby farms and exploring the town and local market. You may also opt to delve into the Vietnamese culture with language, cookery and weaving classes. Savour authentic local dishes and familiar home comfort foods in casual settings. Meet up at the social hubs either indoors or outdoors to talk about the day’s discoveries with other world travelers passing through or laze by the pool and rest up for your big adventure.
Join the
Be the first to get the latest news and updates straight to your inbox.

Recent Posts


Disclosure: This is a for-profit blog and may contain affiliate links, where we receive a small commission on sales of the products or services that we recommend, at no additional cost to you. This does not affect our opinions and we only feature products that we already own or genuinely would recommend regardless of an affiliate relationship. Thank you for supporting Adventure People.