Son Doong Cave Mystery – The World’s Largest Cave

Son Doong Cave-Phong Nha Private Car


Vietnam is an S-shaped country with many breathtaking landscapes. For example, the terraced fields in the Northwest, thousands of unique limestone islands in Ha Long Bay, etc. Especially, Vietnam is currently the country that owns Hang Son Doong Cave  the largest cave on the planet.

The Son Doong Cave-Phong Nha Private Car

The Son Doong Cave is a “monumental, stunning painting” with many uniquely shaped stalactites. The most special thing is that it contains a primeval forest growing inside the cave. World geological scientists consider Son Doong the most magnificent cave in the world.

Let’s Phong Nha Private Car to learn more about the mysteries of the world’s largest cave through this article!

Hang Son Doong Cave Location

Where is Son Doong cave located? Hang Son Doong, the world’s largest cave in Vietnam, is in Phong Nha-Ke Bang National Park. It belongs to Tan Trach commune, Bo Trach district, Quang Binh province.

Hang Son Doong Cave-Phong Nha Private Car

It is a natural wonder with breathtaking views and unique geological formations. Son Dong cave connects around 150 other caves in Phong Nha Ke Bang National Park near the Laos border. Plus, it has a primeval forest and several underground rivers inside the cave, hence the name “Mountain River Cave”. You can see the Hang Son Doong cave map below:

How To Get To Son Doong Cave?

How to visit Son Doonbg Cave? If you are staying in Phong Nha town, you can join in the Son Doong cave expedition 5 days 4 nights. In case you are staying in Dong Hoi city, you should book our Dong Hoi to Phong Nha private car, then join the tour.

Son Doong cave tour-Phong Nha Private Car

If you travel from Ho Chi Minh city, you can book a flight or a train to Dong Hoi Airport or Dong Hoi Train Station. Then, take a taxi or private car to transfer to Phong Nha. In case you are staying in Hanoi, Hue, Danang, or Hoi An, you can refer to our private car transfer service as below:

You may care about our Phong Nha cave tours from 1 day to 3 days and 2 nights as follows:

The Name “Son Doong” Cave’s Origin

According to the tradition of cave experts, the person who discovers the cave will have the right to name the cave he finds. Therefore, the cave experts team asked Mr. Ho Khanh to name the cave. Many people suggested that this giant cave be named Ho Khanh to honor the person who discovered it.

Son Doong cave in vietnam-Phong Nha Private Car
The mysterious beauty of Sinkhole 1 at different times

However, Mr. Ho Khanh and members of the British royal expedition team discussed and named the cave “Son Doong”. It combines two words: Son means mountain, and Doong is the name of the valley where the Rao Thuong river flows through Doong village. This village is where the Bru Van Kieu ethnic minority has lived since 1992.

Son Doong Cave Survey History

When was Son Doong Cave discovered? Early December 1990: Mr. Ho Khanh – a local man, was on a trip to the forest and discovered the cave entrance later known as Hang Son Doong.

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Mr. Ho Khanh – the first person who discovered the Son Doong Cave.

April 7, 2009: Ho Khanh led the headman – Mr. Howard Limbert, with his British Royal Caving Association expedition to survey and measure the cave. Remarkably, Mr. Peter MacNab was the first person to enter the cave.

On April 14, 2009, National Geographic magazine announced and confirmed it as the largest natural cave in the world in the documentary “The World’s Biggest Cave”.

Son Doong cave expedition-Phong Nha Private Car
The cave expert – Mr. Howard Limbert

March 17, 2010: The expedition team climbed the Vietnam wall out of the cave. This event marked the completion of the survey and measurement of the entire Son Doong Cave.

Hang Son Doong Cave’s World Records

In 2013, Guinness World Records recognized it as the largest natural cave in the world. At the same time, the Son Doong Cave was put into operation for tourism and is an international-class tour. In 2015, Guinness continued to recognize Son Doong as the world’s biggest cave in terms of volume (38.5 million cubic meters).

vietnam Son Doong cave-Phong Nha Private Car

In 2014, The New York Times voted Son Doong as one of the 52 most attractive tourist destinations in the world. Plus, Son Doong Cave ranked first in the list of 15 most magnificent caves in the world according to Bored Panda’s poll.

In 2015, the ABC News’ Good Morning America program filmed and broadcast live from inside the cave for the first time. Simultaneously, National Geographic magazine published an album of 360° photos taken very clearly with sound inside Son Doong cave.

Son Doong cave expedition-Phong Nha Private Car

In 2019, artist DJ Alan Walker made a music video called Alone P.II, filmed at Son Doong Cave. Then, he released on YouTube on December 27, 2019. By October 2022, this MV had reached 275 million views around the world.

In 2020, Business Insider honored Son Doong Cave as one of the 20 natural wonders that broke natural records.

In 2021, Son Doong 360 Photo Set on National Geographic became a virtual reality tour. It has attracted everyone in the world during the past pandemic.

April 14, 2022, on the anniversary of Son Doong being announced as the world’s largest cave. Google Doodle has honored Son Doong cave on the homepage of Google’s search engine in 18 countries around the world.

What To Explore At The Son Doong Cave?

Son Doong cave size: Son Doong cave length is nearly 9km, and the cave arch is large, with the highest part being 200m and 150m wide. The experts estimated the cave can accommodate a 40-storey skyscraper. Notably, the volume of the cave is 36.8 million cubic meters (equivalent to 15,000 Olympic swimming pools).

the Son Doong cave-Phong Nha Private Car

With the above data, Son Doong has now officially surpassed the world record for Deer Cave in Gunung Mulu National Park, Malaysia. The Son Doong Cave became the largest, most majestic, and splendid natural cave on the planet.

However, what makes Son Doong special and attracts the world’s attention is the unique world inside the cave. The Son Doong cave contains many stalactites and stalagmites of huge sizes, especially stalagmites over 80m high.

inside Son Doong cave-Phong Nha Private Car

Besides that, it contains the primeval forest growing in the cave, containing the ecosystem. In addition, the cave also has its own weather or endless underground river that no expert has ever discovered.

Many tourists entering the cave think that Son Doong Cave is like another world. Hence, the MC Ginger Zee of ABC News’ Good Morning America program exclaimed that the scenery in the cave is like in the movie “Avatar”. Below are the outstanding features besides many unique things only found inside Son Doong Cave in Vietnam.

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Hope And Vision Cave Branch

The branch of Hope and Vision cave is a straight and large cave, with a length of about 1.5km from the point of crossing the stream inside Son Doong cave to the sinkhole area 1. Hope and Vision has a giant arch where the caves are located.

exploring Son Doong cave-Phong Nha Private Car

This is the largest cave in the Hang Son Doong cave system. Therefore, cave experts estimate it can accommodate a skyscraper of more than 40 floors. Plus, cave experts described it as large enough for a Boeing 747 to fly over the area easily.

hang Son Doong cave tour-Phong Nha Private Car

Inside Hope and Vision is an underground river flowing at a depth of 40m from the explorer’s path. There is a stalagmite named “Hand of Dog” and a giant tall stalactite block named “Hope and Vision.” The giant stalactite column” Hope and Vision” is located behind the underground river inside Son Doong Cave.

Son Doong cave mystery-Phong Nha Private Car
The Hope And Vision stalagmite

In 2009, the British-Vietnamese cave experts measured and confirmed the height of this stalactite block was 80m and is currently the tallest stalactite in the world. Also, on this Hope and Vision stalactite block, famous ABC News MC Ginger Zee sent “Good Morning” to America on the Good Morning America program in May 2015.

Vietnam Son Doong Cave-Phong Nha Private Car

Hand Of Dog Stalagmite

In addition, there is a large stalagmite structure, “Hand of Dog”, located between the areas of Hope and Vision and Sinhkhole 1. It is about 2km from the mouth of Son Doong Cave and about 1km from Sinkhole 1 of Son Doong Cave.

The reason why the Hand of Dog stalagmite in Son Doong Cave has such a huge size – about 60m high – is because it was formed in the cave dome area nearly 100m high. Plus, an amount of water carrying calcium salt (calcium carbonate) flowing down right at this area for hundreds of thousands of years.

Son Doong cave documentary-Phong Nha Private Car
The Hand of Dog stalagmite

During the 2009 trip to survey and measure Son Doong Cave, the expedition members were divided into groups of 2 to survey and measure the cave with laser equipment. Experts Helen Brooke and Trevor Wailes were assigned to survey the large area of the cave and map the area. Because the cave is so wide, experts must segment and name each corridor for easy identification.

Helen Brooke was responsible for going ahead and measuring the parameters of the cave using laser equipment. Trevor Wailes followed behind and was responsible for recording measurement parameters and describing the cave area as a basis for drawing a map.

Hand of Dog in Son Doong-Phong Nha Private Car

As she approached the area, Helen saw a rock protruding like a child’s hand, as in a children’s television series she had just seen in her hometown. The shadow of the rock became clearer from the faint rays of light shining from Sinkhole 1 more than 1km away. She decided to name this area the Hand of God.

However, because Mr. Trevor stood at a distance and could not hear clearly, he thought that Helen named her Hand of Dog, so he put this name on the map. Once the Hand of Dog stalactite name is recorded on the cave survey map, no one can change that name anymore.

Son Doong cave mystery-Phong Nha Private Car

Hand of Dog in Son Doong is an iconic stalactite. Visitors can see this stalactite silhouette looming up before approaching from the Hope and Vision side, looking from afar towards the Sinkhole 1 area. In addition, the light from Sink Hole 1 and the mist creates a magnificent scene of the world’s largest cave.

Underground River

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Son Doong Cave possesses a large underground river system formed by the intersection of two rivers. It is the Rao Thuong river and the river from Khe Ry Cave, with water originating from the Laos border. Before entering the Hand of Dog area from the cave entrance, you must cross two streams at about knee-deep depth.

Son Doong Vietnam-Phong Nha Private Car
Underground river inside Son Doong

When the water level is higher, there is an elevated walkway using ladders. When the river flows into the cave, it creates many waterfalls with a 5-10m height. The waterfalls create echoes throughout the cave dome and simultaneously create a lot of steam and clouds of fog that sometimes cover the entire cave dome. This underground river disappears near sinkhole 1, about 4.5km from the cave entrance.

how to visit Son Doong cave-Phong Nha Private Car

The underground river continues to flow inside the cave, and the cave dome has a height of 150-200m in areas where the underground river in Son Doong Cave flows through. Below is an underground river flowing at 40-50m depth. The underground river in Son Doong Cave continues to flow to the Sinkhole 1 area. Then, it falls into a 40m deep waterfall before disappearing from Son Doong Cave.

Son Doong cave photos-Phong Nha Private Car

Experts suspect that the underground river of Hang Son Doong connects to Hang Thung (a cave geographically located 600m away). On March 31, 2019, an expedition team led by Mr. Howard Limbert and some of the world’s best cave diving experts conducted survey dives in an underground river in Sinkhole 1 to find this connection.

Son Doong underground river-Phong Nha Private Car

After nearly a week of surveying, the experts discovered an underground passage at a depth of 90m. However, they stopped the survey due to a lack of diving equipment at great depths. If this underground cave section connects to Hang Thung, the volume of Son Doong Cave will increase by 1.6 million m3. Further expeditions will be carried out soon.

Fossil Passage

The Fossil Passage is an area in Son Doong with cave walls filled with coral fossils, snails, shellfish, and fish bones over 300 million years old. Its location is right next to the underground river at a depth of 40m, below the first campsite – Sinkhole 1.

hang Son Doong cave map-Phong Nha Private Car

This is also an underground lake with a temperature of about 16 to 17 degrees Celsius. So, it is where visitors can wear life jackets and use headlights to swim and relax after a long day of trekking from En Cave. Most tourists think swimming in the cold underground river is one of the experiences not to be missed when joining the Hang Son Doong Cave tour.

Son Doong cave location-Phong Nha Private Car

With the diversity of species, coral layers, and secrets hidden behind limestone layers, the Fossil Passage in Vietnam is an appealing attraction for domestic and foreign tourists. Plus, it also attracts scientists, archaeologists, geologists, and paleontologists.

Sinkhole 1: Watch Out For Dinosaurs

Sinkhole 1 (Doline 1) is where the cave arch has collapsed to form an area of skylights leading to the outside. According to measurements of the British-Vietnamese caving team, sinkhole 1 has a depth of 449m from the lowest point of the crater to the bottom of the cave. The widest area in sinkhole 1 was recorded at 125m.

Son Doong cave size-Phong Nha Private Car

On sunny days, Sinkhole 1 receives a lot of sunlight from about 11 am to nearly 1 pm. Especially from January to March every year, the Sun’s rays shine deep inside the cave, brightening up the vast dome. However, rays of sunlight can appear on any sunny day of the year, creating one of the iconic scenes of Son Doong Cave.

Hang Son Doong Cave-Phong Nha Private Car

When passing through the Green Gour area, this is the most beautiful and unique area of Son Doong cave. From here, looking up at the sinkhole, you will understand why Sinkhole 1 is named Watch Out for Dinosaur. At first, when the first two experts came here, seeing the pristine scenery, they marveled that the area was like Jurassic Park.

Hang Son Doong Cave-Phong Nha Private Car

Coincidentally, the children of these two experts are also very fond of dinosaurs. They said to each other: “Imagine what our children will say when they see this scene; they will surely scream: Daddy! , daddy! Watchout for Dinosaur!

Below Sinkhole 1 is a giant stalagmite that is the Wedding Cake stalagmite. Its surface is quite flat because frequent waterfalls are on top of the stalactites. However, it is still composed of calcite in the form of rimstone or gourd dams and contains cave jade.

Son Doong cave wedding cake-Phong Nha Private Car
The Wedding Cake stalagmite

The Son Doong Cave Wedding Cake stalagmite block is round like a cake, and someone once stood here to propose. Since then, many Vietnamese tourists have called this unique stalagmite the Wedding Cake. It is a symbol of the cave that famous American MC Ginger Zee said that the scene here is like in the movie “Avatar”.

Son Doong cave photos-Phong Nha Private Car
The calcium rim is like a terraced field shape.

Behind the wedding cake area is a large area of Phytokarst, a rare structure from cave formation. Looking ahead, you will see blocks of calcium rock covered green by many species of moss and algae. They are arranged in steps like terraced fields in the northwest region of Vietnam. Visitors will have to move a detour to protect this Green Gour area.

Hang Son Doong Phong Nha-Phong Nha Private Car
The campsite area

Sinkhole 2 – Garden Of Edam

During a survey and measurement trip to Son Doong Cave in 2009, it was called the Garden of Edam because the expedition team supposed it was like a fairy tale garden. Therefore, they wanted to name the forest Garden of Eden. However, they changed it to “Garden of Edam” to avoid misunderstanding the use of names in religion.

Son Doong cave forest-Phong Nha Private Car

The Sinkhole 2 has a height of more than 250 meters, about 175 meters wide. Hence, it is enough light for a whole Son Doong cave forest to develop. Due to the characteristics of the forest located deep underground, the old trees often have small but very tall trunks up to 40-50m in height.

Garden of Edam-Phong Nha Private Car

Here, cold, moist steam is blowing out from the cave, so you will often encounter mist covering the path from inside the cave to the forest. The scene becomes more unique and magical when the mist disappears and appears. It makes the forest sometimes full of fog, sometimes clear with tall trees.

Son Doong cave forest-Phong Nha Private Car
The sinkhole view from above

Besides the diversity of plants, in Sinkhole 2 – Garden of Eden, there are also some typical animals, such as flying squirrels and snakes. Occasionally, a group of monkeys come down to look for food. Besides, many other species live in different conditions between the forest and the edge of the cave dome.

Strangely, there is a bird that often flies around the sinkhole and inside the cave in the early morning. If you are lucky, you can hear the very loud flapping of wings of this bird, according to the conjecture of cave experts. It could be an owl or an Eagle Owl.

how to visit Son Doong cave-Phong Nha Private Car
Doline 2 Campground

In addition, the Sinkhole 2 campground is the place that receives the most light from the outside. The campsite is located right on the sandy beach at the edge of the cave dome, so it remains dry on rainy days. You must trek over 30 minutes to cross this forest to enter the Sinkhole 2 camping area.

Son Doong cave forest-Phong Nha Private Car
The Sinkhole 2 at night with many stars on the sky

Therefore, you can drink coffee at this campsite while watching the starry sky above Sinkhole 2 at night. Otherwise, you can also watch Son Doong cave clouds in the Garden of Eden in the early morning.

You can also watch the waterfalls flowing down from the cave’s dome on heavy rainy days. They create an extremely magnificent scene in the cave. The camping ground here is considered the most beautiful in the world. It has a primeval forest underground with a separate climate system compared to the outside.

Cave Pearls

Son Doong cave pearls-Phong Nha Private Car

These are calcium stones formed from drops of calcium-carrying water from the cave ceiling dripping onto the calcium seams below the cave floor. In many areas inside the cave, there are many cave pearls of many different shapes and sizes, from as small as beans to as big as baseballs.

The cave gems are naturally arranged inside the calcium seams, and they look very beautiful when illuminated with light. Especially on days when rainwater drips down, these cave pearls look sparkling under a flashlight.

Son Doong cave pearls-Phong Nha Private Car

However, these Son Doong cave pearls are just ordinary calcium pellets with no value. Hence, they will change color and become ugly when brought outdoors under direct sunlight.

Passchendaele Passages

It is a lake below the Great Vietnam wall, with a length of more than 600m. When the cave expedition approached this area, all the water in the lake had drained away, leaving a waist-deep muddy path. The expedition members had to work very hard to cross this muddy 600m passage.

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This passage reminded them of the movie of the same name about the Passchendaele battle in World War I. Hence, the cave expedition team used the name Passchendaele to name this long and arduous passage.

However, during many other months of the year or when there is a lot of rain, the water will rise to fill the shallow stream. Thus, it forms a large lake at a length of 600m with a very beautiful jade green color. During the months when the lake is full of water, you will use a raft or kayak to move through this Passchendaele Passage.

Son Doong cave photos-Phong Nha Private Car

The Great Wall Of Vietnam

In April 2009, after nearly 5 days of surveying and measuring Son Doong Cave, the expedition team encountered a giant block of rock blocking all paths. Because they did not bring appropriate equipment, the expedition experts could not get over it.

The Great Wall of Vietnam-Phong Nha Private Car

At this time, no one knew what was behind that large block of rock and how far away it was. The expedition team decided to name the block of rock “The Great Wall of Vietnam” to express the majesty that experts could not pass at that time.

In March 2010, the expedition team prepared all appropriate equipment to overcome “The Great Wall of Vietnam” – the giant wall in Son Doong Cave. They accompanied the National Geographic TV television crew to record the survey process and witness the process of overcoming the 90 m wall.

Great Wall of Vietnam-Phong Nha Private Car

At the Great Wall, expedition experts spent 2 days drilling locations to attach safety hooks and using ropes to climb to the top of the wall gradually. Cave experts Gareth Sewell (Sweeny) and Howard Clarke (Clarkey) were the first two people to climb the wall. Plus, they were also the first to set foot in the back area of the Vietnam wall.

Gtreat Wall Vietnam-Phong Nha Private Car

The wall has a height of 90m with a slope of 45 degrees. When he reached the top, he saw some light in the distance, so he thought this was the exit of Son Doong Cave. The distance from the Vietnamese wall to the entrance of Son Doong cave is 500m.

Frequently Asked Questions

Why is the Son Doong cave tour priced at $3000 a person?

Tour Son Doong cave price is 72,000,000 per person in VND for 6 days and 5 nights. Son Doong cave expedition tour price includes VAT, entrance fee, and forest environmental service fee (600 USD). In addition, there is a management fee and a monitoring fee for the national park (20 USD). Son Doong Cave ticket price includes the following package services:

Son Doong cave tour price-Phong Nha Private Car

  • Pick up and drop off at Dong Hoi airport/train station.
  • Service team: Each tour of 10 guests will have 1 cave expert and 1 tour guide. Plus, 6 safety assistants, 2 chefs, and 17 luggage porters.
  • Meals: Food, tea, and coffee will be provided to you during the journey (excluding extra things you require). Dishes follow a fixed menu and can provide vegetarian or dietary dishes upon the prior request of guests. Please refer to the menu when booking the tour.
  • Rest: Guests will stay at Son Doong Bungalow the first night, 3 nights in a tent in the cave. Plus, 1 night at Chay Lap Farmstay after leaving the cave.
  • Safety equipment: You will be provided with safety equipment such as helmets and seat belts. Plus, expedition headlamps, gloves, and other safety equipment.
  • Travel insurance: You will receive compensation as Vietnam Tourism law requires, with a maximum of one case of 50 million VND.

Son Doong cave tour price-Phong Nha Private Car

How many Son Doong cave tours are organized in a year?

In contrast to other types of tourism, Son Doong Cave is one of the few in the world that limits the number of tourists. Each year, the number of visitors is limited to only 1,000 persons. This aims to conserve resources and ensure visitors enjoy the best experience.

Phong Nha Cave Tours-Phong Nha Private Car

Therefore, each month will have about 13 – 15 tours organized to explore Son Doong cave in Vietnam. Plus, each tour is only for small groups of 10 persons over 18 years old at maximum. Every year, the Hang Son Doong cave tour is available from January to August. Thus, the remaining time is devoted to restoring the ecosystem.

What to prepare before exploring Son Doong cave?

Hang Son Doong Vietnam-Phong Nha Private Car

Son Doong Expedition Tour is a day-long trekking tour going through many different types of terrain. Depending on the tour’s departure time, you will need to make your own thoughtful preparations to ensure a complete experience. The luggage you need to prepare includes:

  • Passport, 1 backpack (20L-25L), backup battery
  • Sunglasses, sun hat, sunscreen, mini fan (in summer).
  • Mosquito repellent cream, shampoo, and shower gel are environmentally friendly.
  • 3-4 long-sleeved, light-colored, quick-drying trekking shirts
  • 1 windbreaker (in winter)
  • 2-3 long, quick-drying trekking pants
  • A pair of climbing shoes that drain water quickly because you have to wade a lot in streams
  • 4-5 pairs of thick, high-cut socks
  • 1-2 sets of clothes to bring while at camp
  • 1 pair of sandals or sandals (at camp)
  • 1 swimsuit, 2 towels, underwear, personal toiletries
  • Personal medicine and anti-calluse bandages.

Important notes: Do not bring skirts, dresses, or elaborate costumes. Medical experts will check your health to ensure you can participate in the trip.

Trekking to Hang Son Doong-Phong Nha Private Car

Before exploring Son Doong cave, you should practice walking about 10km/day. Additionally, you ought to cross at least one hill about 200-300m high. You should persist in practicing for 3 – 6 months to have enough strength to join this wonderful journey.


On the whole, the journey to explore Hang Son Doong cave in Vietnam will certainly be a memorable and meaningful experience in your life. You will witness one of the most magical and majestic natural masterpieces on this planet. Phong Nha Private Car wishes you a memorable experience at the Son Doong cave in Vietnam!