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. 

Check out this stunning drone footage of a recent trek to Son Doong Cave.

Oxalis has maintained its exclusive position in Vietnam as the only tour operator of treks to Son Doong Cave due to its commitment to technical safety on all its tours. Oxalis understands that with a big cave comes big responsibility, and ensures all guests are led by the best international caving team in the world, alongside a team of exceptional local cavers and guides.

If you would like to join a trek to Son Doong Cave there is limited availability for trips departing in 2019. Check dates and make reservation here: Son Doong Cave Expedition

Discovery of Son Doong Cave

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 modest income.

In 1990 while out on a hunting mission, Ho Khanh stumbled across 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 feel a strong wind also 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 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 more.

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 ‘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.

Geology & Size of Son Doong Cave

The Phong Nha-Ke Bang National Park in Vietnam contains the oldest karst system in Asia, between 400-450 million years old. Hang Son Doong itself is relatively young, with the analysis of sediment dating it to be only 3 million years old.

Formed on the edge of a fault zone, Hang Son Doong has been carved out by the mighty Rao Thuong River as it erodes away the limestone, forming the enormous tunnel beneath the Annamite Mountains. Giant sinkholes, known as dolines, have collapsed sometime up to 300’000 years ago, creating massive openings to the outside world. Cave pearls the size of baseballs have been formed by water dropping from the ceiling.

The first expedition had been halted by an 80m high calcite barrier, which was jokingly dubbed the ‘Great Wall Of Vietnam’. It wasn’t until their second expedition in 2010, when the Great Wall was finally climbed and the end of the passage was found, that Hang Son Doong was determined to be the largest cave in the world.

At over 5km long, with sections reaching up to 200m tall and 150m wide, Hang Son Doong is large enough to house an entire New York City block, complete with 40 story skyscrapers. With a total measured volume of 38.5 million cubic metres, this comfortably surpasses Deer Cave in Malaysia, which was considered to be the previous record holder. Stalagmites up to 80m high have also been surveyed, the tallest ever encountered.

Cave experts are doing researches about the connection of Son Doong Cave & Hang Thung Cave, the final result will soon be updated. Find more information about the Diving Expedition inside Son Doong Cave.

Trip Advisor Reviews

Read a very small selection of unedited TripAdvisor reviews of Son Doong Cave. It is continually rated as the best trekking experience in the world and truly life-changing:

“One of the Most Memorable Things I’ve Ever Done” – Tap1 (New York)

If you are on the fence, just go!! Just got back to the States from Asia and was on the April 17 trek to Son Doong Cave. My friend and I wanted to do something out of our comfort zones and this was definitely it in the best way possible. It was the highlight of our 3 1/2 week trip through Asia, and we felt empowered when we finished.

“Once in a Lifetime Experience” – Ryan M (Los Angeles)

Don’t think twice – just do it. This was such an incredible experience. Oxalis is such an incredible company in terms of organization, community involvement, and overall quality of the expeditions. Words can’t really capture the immensity of Son Doong so I’m not even going to try. All I can say is that it’s unlike anything you’ve ever experienced. The food is phenomenal, the guides and porters are incredibly kind and knowledgable, and the location can’t be beat.

“Possibly the Most Incredible Place on the Planet” – Akostich (Los Angeles)

I just returned from the 5 day expedition into Son Doong Cave, and it was incredible. Having been to over 70 countries I can say that I have not been as astounded by the sights before my eyes anywhere else in the world.

“My Top Trek and Destination!” – Reap9196 (Sydney)

There are some treks in the world that are all about the journey and not just the destination. Son Doong is a world ahead on both the journey and the incredible destination. Each day when we would get to camp, a coffee was always there and I just could not believe the sights I had seen.

Oxalis are world class and they really do make the journey so enjoyable. I was concerned about doing this as I am getting old but I did it and I had nothing to worry about. You will need to train and you will need to be prepared to be wet as you cross lots of rivers but that makes it fun. I loved every minute of this trip and it is like nothing else on earth. I felt so humble and so into the now like never before. A truly life changing experience with an incredible company. Book well in advance and don’t think twice it is worth every penny and more.

“Surreal, Out of this World Experience!” – Yohendran B (Singapore)

You definitely need mental strength and fitness for this, but it’ll be worth it. A 4 day jungle/cave trek which was more tricky than exhausting and well supported by the exclusive Oxalis tour group. Be prepared for wet feet, pack light, keep your concentration for safety and stay hydrated. Awesome scenery, huge caverns, subterranean rivers, fossils and great camaraderie.

“Amazing Experience Visiting Son Doong Cave with Oxalis!” – Cristina D

Amazing experience being part of Son Doong Expedition in July 2018! Oxalis is a very professional company, and everything was well organized from the beginning to end: the emails with preparation details before arrival, the quality of accomodation provided by Oxalis on first and last night of the tour, the cleaness of the campsites, the guidance and safety measures along the way.

Oxalis are the sole tour providers to some of the best caves in Phong Nha Ke-Bang National Park: Son Doong (largest cave in the world), Hang En (3rd largest), as well as other caves. Besides being professional in delivering the service to tourists, they are also very well aware of the fragile environment we step in, and they are continuously watching and protecting it.

“Son Doong Expedition – Once a Lifetime Experience!” – Cindy L (Los Angeles)

Ever since I got back from Son Doong I’ve been telling everyone that they should do it as soon as they can – Son Doong is so beautiful that you have to experience on your own, photos or videos never do the justice. It makes you realized the world has so many wonders to offer, that you need to see, touch and feel before it is gone!

With Oxalis’ service, visiting Son Doong is like doing a one-day hike in Griffith Park – you basically carry your water bottle and helmet and that’s all! The safety assistants and the porters are amazing – they prepare everything you need for you. Everyday when you arrive the campsite, the tents and restrooms are already there. The safety assistants even make you tea and coffee for you! I felt I was treated like a queen! Let alone the amazing meals the chef makes – you seriously won’t find better food in Phong Nha other than in Son Doong!

Mostly importantly, I felt super, super safe everyday. Even we had to climb up and down so many times, I knew I was being taking extremely good care and I didn’t have to worry about falling or anything else. If you are an experienced hiker and have strong legs and good balance, SonDoong is easy and has tons of fun!!! Just go and enjoy the beauty!

“The Son Doong expedition – A Once in a Lifetime, Totally Unique Experience!” – PrinaP (Nairobi)

We just completed the 5-day, 4-night Han Son Doong expedition with Oxalis and I can safely say it is like nothing I have ever done before. The trek to and through the cave is intensely physical and I can see why they say they’ve had to turn people away before – a word of advice…definitely follow their advice on how to train!

Having said that, we never felt rushed in the cave, and we never felt unsafe because the team are all consummate professionals – everyone from our main guides Thang and Adam, the assistant guides Bien, Hoay, Ling and Dang, and the staff in the head office were wonderful. Our main chef Bun kept us really well fed (I already miss my daily pho breakfast) and the team of porters ensured camp was always well set up by the time we reached at the end of the day.

This type of trip is not for the faint-hearted, but if you’re willing to put yourself out of your comfort zone and want to see landscapes and formations that few will ever see, sign up…immediately!

My girlfriend and I booked the 4 day son doong adventure with Oxalis. Let me first start off by saying this was a once in a lifetime experience and the group i had in the trip made it memorable and i will never forget this. Everything was rolled into one price which made it very easy.

The Chay Lap farm stay the first night was very nice and the service there was tremendous. We were picked up and dropped off at the airport, even driven there early for a special time flight. We were informed very well on what to expect and what was expected of us. The 2 guides we had were tremendous, try to go with them if you can. Wotto and Anetta were our guides, cant say enough good things about them. The porters that joined us were very nice and it made the experience even better.

Each of the 3 campsites were already set up when we arrived and the boys that came along as porters cooked some amazing meals! By day 3 we were all very close, even with the porters and guides. Our final dinner was a sad goodbye, we didn’t want to leave the group. We had so much fun, a once in a lifetime experience. Wotto our guide showed me some amazing ways to take photography. Anetta our other guide provided some great laughs.

We left after 4 days with hugs for everyone, i even had to give the porters hugs as i felt close to them after just 4 days. I highly recommend to book a trip with Oxalis. I am biased to Wotto and Anetta as guides but if you can request them!


Available Trekking Dates

The rights to visit Son Doong Cave have again been awarded by the Vietnamese Government to Oxalis Adventure Tours for 2019 and 2020 season. Oxalis are a locally based tour company in the Phong Nha Ke Bang National Park and selected due to their professionalism, safety, environmental and conservation efforts.

Oxalis does not operate the tour all year due to risk of flooding during the monsoon season, which starts in November and runs through till mid-January. Safety is a core value for Oxalis and no exceptions will be made to visit the cave during the rainy season.

There is currently availability in 2019. Booking must be made before arrival in Phong Nha to ensure your place on the limited departures available. Oxalis use a simple booking system calendar similar to when searching for a flight. Available dates will be displayed in your preferred week or month.

The price is USD 3000 which includes one night in Phong Nha before the trek (due to early departure the following morning), one night camping in Hang En Cave, two nights camping at different locations in Son Doong Cave, and one night accommodation in Chay Lap Farmstay due to potential late return on final day. It also includes the National Park Permit which is upwards of USD 700 per person, all meals, safety and camping equipment as per the inclusions listed on the tour page.

You can check availability and make a booking by visiting our: Son Doong Cave Expedition Availability Calendar

Alternatively, please don’t hesitate to contact our team directly to answer any of your questions via email: [email protected] or phone: +84 (0) 919 900 042.

Difficulty of Son Doong Cave Trek

Son Doong Cave is considered a level 6 on the list of Oxalis Adventure Level. That being the highest level of difficulty. However, with that said if you keep a regular fitness routine at home you should be able to complete the trek, and it is as much a mental challenge that requires stamina and determination.

If you are a bit slower then the rest of the group, don’t worry you will not be turned around. We do have a whole team of safety experts and guides to assist you with your footing along the way. Of course, this is within reason and our guides should not be relied upon for the entire trip.

To give you a complete perspective we have lifted a number of reviews from Trip Advisor commenting on the difficulty of the trek, which may or may not make it easier for you!

“Amazing experience and don’t let the physical stuff scare you” – Joseph L (mid 30s male)

For those who are reasonably fit, and perhaps even those who do not exercise a few times a week, this is not that difficult a trek in terms of cardio. Some of the other posters here make it sound like hiking Son Doong is akin to Army basic training or something. I assure you it is not. Look at Oxalis’ actual physical checklist. You’ll see things such as “Can you climb six flights of stairs without stopping or getting out of breath?” or “Can you easily climb over a wall the height of your waist?” I found that relatively modest amount of fitness to be adequate for our good-weather trip (muddy but no rain. low 90s in daytime but cool at night and cool in cave). I bet doing it in, say, August is more difficult.

Some perspective on us…mid-30s. Longest recent one-day trek we had done before this was 20km. Longest recent multi-day trek we had done was Inca Trail. Not overweight but not hitting the gym every day either. We did not find the most difficult day on Son Doong to come close to the effort of that one-day hike or to the most difficult day on the Inca Trail. There were a couple older less fit (and a bunch of older and younger, more fit) people than us on the trail. Everyone seemed to make it through comfortably. It’s not a race and when you get tired or winded, you stop.

The more-unique physical challenge is the type of terrain, balance, and mental focus required. The cardio is easy, but this is one hike where it feels like you could break an ankle on almost every step. Extremely sharp rocks that you sometimes must balance on. Everything is slippery. Always searching for handholds. Often getting on your knees or butt to keep from falling over. And doing that for five hours or whatever straight a day.

That was the challenging part for us. It was just mentally exhausting after a while to always be worried about making the right step. The guides and safety guides (probably more than one for every two tourists) are always there to help.

“Another world” – T4tillerman (mid-50s woman average fitness)

You must be very fit and have great stamina. This is not an easy trip. It. Is. A. Challenge! For 5 days you will be trekking through the jungle in extreme heat and humidity, climbing over slippery, sharp rocks in near dark and climbing down again, crossing too many rivers to count both above and below ground and dealing with elements foreign to most of us. The over 50 kilometres are not easy ones.

You will be camping and cannot expect to be clean, dry or particularly comfortable in this world. Be honest about your abilities and realistic about physical comfort in these conditions. Good hydration is not just extremely important; it is vital! Drink and then drink some more. Do not worry about having to urinate, you will sweat it out. I averaged 3 litres a day on the trail and drank a lot in camp. 

Take every piece of advice Oxalis gives you seriously. They know what they are talking about. You are in good hands.

Just Unbelievable. Needs to be Experienced as it can Hardly be Described! – Kim J (good fitness)

Beforehand, I was slightly worried that the hot climate would be an issue for me – knowing that I get overheated and dehydrated easily in hot tropical weather. I filled my 1-l water bottle each morning with ORS powder to keep hydrated well which was very helpful, and luckily inside the cave the temperature dropped somewhat to a more agreeable level.

The physical activity itself was not an issue for any of our tour members; I think that with reasonable fitness and relatively strong legs the tour is very doable. We trained with a few multiday mountain tracks over two months prior to the tour and this was sufficient for us. The most strenuous activity of the whole tour I’d say is climbing the great wall at the end, however this is quite doable too since it requires only about 5-10 minutes of your strength ;-). Ah man just writing this review makes me want to go again!

Book It. Now. – Jon S (40s male average fitness)

If you’re not sure whether you want to do this, but you like any of: hiking, camping, one-of-a-kind experiences. Then just do it. You don’t need to be an elite athlete, you just need to be in reasonable shape. If you work out and regularly do physical activity and are in decent shape, you’ll be fine. The cave is absolutely amazing, the experience is unique, and you will not regret it.

Great for your Adventure Vacation! – Gazbostock (UK)

Physical Challenge: This tour is VERY physically demanding. That being said, people of all ages and body types do this tour because it is said that even the fittest crossfitters are not always the ones who do the best here. It’s the terrain that people are not used to, and being a gym rat does not necessarily prepare you for it. But you are accompanied by AWESOME safety assistants who will sometimes literally hold your hand through the hardest parts. Just make sure you’re flexible (you’ll be doing a lot of reaching for the next ledge), that your knees are healthy, and that you’ve got good mental endurance. (That last day feels so long.

Drop Whatever You Are Doing – Go To Son Doong Cave Now!!!!!! – Paul C (experienced trekking) 

Hints: follow all preparation and equipment recommendations. Do not fool around or get “cheap” or overly frugal. Footwear is by far the most important item on the list – take it seriously. If you have any questions or concerns email Mo (her assistance is invaluable – love her). Travel light and lightweight – get quality “stuff”. For me practicing Bouldering is much more valuable than technical climbing. Cardio – the Stairmaster will not only get in condition but build strength as well – use it often. Best recommendation I have is getting some brand of electrolyte tablets – we used Hammar brand. The powders are not practical in the cave. The tablets were fantastic and easy.

Challenges: Okay I will be honest I had “Great Wall” anxiety from the moment I signed up and paid. There was a part of me that was hoping the cave would be closed or flooded when I arrived because in general I don’t like heights and was “concerned”. Let me put your fears aside. You can and will be able to climb the Great Wall of Vietnam. The three days leading up to it will 100% prepare you to accomplish it. The guides are experts and supportive. It happens so quick you’ll forget about your worries before you have time to worry.

Son Doong Cave Tour Operators

Son Doong Cave is operated exclusively by Oxalis Adventure Tours. Oxalis are the first adventure tour company in Phong Nha and part of the initial efforts to explore Son Doong Cave through their support of the British Cave Research Association.

Due to environmental and safety and according to decree number 1213/UBND-VX dated on August 03, 2016 by the Government of Quang Binh Province, Vietnam, has granted permission to only one tour company, Oxalis Adventure Tours to bring tourists to Son Doong Cave.

Oxalis takes its position in the adventure tourism sector and Vietnam tourism very seriously and strives to create the safest adventures possible for its staff and guests. Oxalis operates on an international level of quality employing one of the top caving groups in the World to oversee all caving operations.

Visiting a developing country has inherent risks as standards are usually lower then what you might expect in US, UK, Europe or Australia. Oxalis sets the standard for adventure tourism companies throughout Asia.

It is the vision to be the best tour operator in the World and therefore we implement strict policies in dealing with safety, local community and the environment. It is for these reasons why Oxalis has been awarded with the rights to operate treks to Son Doong Cave.

Due to the nature of the cave, it is impossible for more than one company to operate  tours at the same time. The pristine nature of the cave would simply be lost if another company were to start operating tours to the cave. Oxalis is extremely proud of Son Doong Cave and what it has done for the entire region of Vietnam.

To learn more about the Oxalis story and our family check this video out:

Son Doong Cave Trekking

Nearby Caves to Visit in Just 2 Days

Whilst Son Doong Cave is the largest cave in the world, there are other caves in the Phong Nha Ke Bang National Park that are also very impressive and worth visiting if either your time or budget doesn’t lend itself to visiting Son Doong Cave.

The next best thing is Hang En Cave, which forms part of the Son Doong Cave System and is actually included for one night of the official Son Doong Cave Expedition as you must pass through Hang En to reach Son Doong.

Hang En Cave is the second largest cave in Phong Nha Ke Bang National Park and the third largest cave in the World, and can be visited on a two days/one night trek for less than $350. It is extremely good value and the cave is outstanding. Average fitness level required – just one big hill to climb on the second day.

Check out a clip of the Hang En Tour prepared by one of our guests:

Hang Va Cave Tours Vietnam

Nearby Caves to Visit in Just 2 Days – Hang Va Cave

Another equally impressive cave is Hang Va, which is in theory connected to the exit of Son Doong Cave through the water, though the connection has not been explored. Hang Va is wonderful with formations that do not exist anywhere else in the world. It is a completely alien world.

Hang Va is can be visited on a two day/one night expedition and costs around $350 per person with regular weekly departures.

Check out this video of Hang Va prepared by one of our guests:

Son Doong Cave Expedition

Only 100 spots left in 2019

This incredible Son Doong Cave Expedition will give you a wonderful chance to explore the world’s largest cave and exit via the Great Wall of Vietnam. This is the only tour available of Son Doong Cave by the official tour operator Oxalis Adventure Tours. 

4 Days / 3 Nights

VND 69,800,000 or US$3,000/pax

Find Out More