After thousands of years of geological transformation, nature created magnificent masterpieces in the Phong Nha—Ke Bang National Park area. Specifically, Son Doong Cave in this park, also called Hang Son Doong, has become the largest cave in the world. It contains a forest and many mysteries, attracting those who love nature and adventure travel.
All photos in the post come from Oxalis Adventure. Thank you!
1. Where is Hang Son Doong?
Address: Phong Nha – Ke Bang National Park, Son Trach Commune, Bo Trach District, Quang Binh Province, Vietnam
Here is the Google Maps of Hang Son Doong from Dong Hoi City, Quang Binh Province:
Meaning of the cave name:
The cave is called Son Doong, meaning Doong village in the mountains. “Sơn” means “Mountain”, and “Đoòng” is the name of a small village of an ethnic minority group living near the cave area, which today, on the way to explore this famous cave, the group will pass through.
2. The story of discovering the world’s largest cave:
In 1990, on a trip through the old forest to find agarwood—a rare natural product—hoping to change his life, Mr Ho Khanh accidentally discovered a cave while hiding from a sudden storm that came to Phong Nha mountain forest.
While standing close to the mouth of the cave, he felt the wind whistling through his body as if a legendary monster were coming from inside the cave.
Over time, Phong Nha—Ke Bang became a nature reserve, and people could not enter the forest to exploit its products. From then on, Mr Ho Khanh no longer went into the forest and forgot about this cave.
It was not until 2001 that the British Royal Caving Association came to Quang Binh to survey and search for new caves in the limestone mountains. Through the introduction, the Association found Mr Ho Khanh and listened to every detail he told about the cave’s accidental discovery in the past. From the initial impressions of his details, the explorers determined this could be a large cave, so they started going through the forest to search.
However, through trips in the forest, climbing passes and wading streams, the whole group could not find any traces of the cave entrance because, over time, the forest trees changed, and there were no trails left.
Luckily, in 2008, Mr Ho Khanh found the cave entrance where he had previously taken shelter from the rain. In 2009, the British Royal Cave Association cooperated with the National Park and Mr Ho Khanh to survey and measure more deeply into the cave.
3. Outstanding features of Son Doong Cave
3.1. Size and scale:
According to the British Royal Cave Exploration Association estimate, Son Doong Cave has a volume of about 38.5 million cubic meters and can contain 37 large civil aircraft or a modern neighbourhood with buildings up to 40 floors high.
Specifically, Son Doong Cave is 200 meters high, 175 meters wide and up to 9.4 km long.
3.2. Landscape inside the cave:
The cave has a richly developed forest with tall, leisurely trees, shrubs, mosses, and ferns. This complete ecosystem of a primaeval forest is typical of the humid tropics.
The stalactites formed millions of years ago and have different shapes, such as the stalactite wall (Vietnam wall), dog’s paw, and stalactite tower. The cave pearls, which are spread across the floor, range in size from ping-pong balls to tennis balls.
Adding to Son Doong’s beauty are the underground streams and clear blue lakes created from streams originating from the surrounding limestone mountains. These streams weave through the canyons to create flows in the world’s largest cave.
Son Doong Cave does not have just one straight path. Still, it forms smaller branches and sinkholes, creating various shapes and increasing mystery.
Sinkholes in caves are where the soil and rocks fall during the geological formation process and the impact of the creation of underground streams inside the mountain.
In sinkholes, fine sand, like sea sand, is often present, transformed over time by nature from the alluvium of the underground river.
4. Son Doong Cave Expedition Tour 4 days 3 nights
Son Doong Cave Expedition Tour is considered one of the outstanding adventure tours in Vietnam. It is highly difficult and includes jungle trekking, cliff climbing, stream wading, swimming, rowing, and camping.
The Son Doong Cave itinerary includes 4 days and 3 nights. However, you need to arrive in Phong Nha 1 night in advance to prepare and 1 night to rest and recover after finishing the jungle trip. Therefore, the total time is 5 nights and 4 days for the mysterious and majestic cave journey in Phong Nha – Ke Bang National Park.
4.1. Price and how to book the Son Doong Cave Tour:
Currently, only Dat Me Travel Company (Oxalis) is licensed to operate the Son Doong Cave Expedition Tour.
All bookings must be made in advance through the company’s website. According to the website announcement, the 2025 tour program is fully booked, so the earliest you can conquer this spectacular cave is 2026.
The Son Doong Cave Tour currently costs VND 75,000,000, which is USD 3,000 for one person for a group of 6 to 10 people.
Conditions: Participants must be 18 years or older, in good health, and pass the company’s health check during the tour preparation and one day before at the office.
4.2. Tour includes:
- Tour guide, cave expert, support staff, chef, porter
- Meals: Breakfast, Lunch, Dinner according to the itinerary
- Airport or hotel pick-up and drop-off upon request
- 1 night at Commander Lodge Phong Nha and 3 nights in tents
- Protective gear and travel insurance
4.3. You need to prepare:
- Personal items such as toothpaste, dry shampoo, etc.
- Enough clothes for trekking through the forest for 3 nights and 4 days
- Mountain climbing and waterproof shoes
- Long-sleeve garments to protect against insects
4.4. Daily Itinerary:
Day 1: From Oxalis office to Hang En
On the morning of the first day, after eating and preparing luggage, the group will start to depart. The destination of today’s jungle journey is Hang En, considered the gateway to Son Doong Cave.
Hang En stands out with its fine sand area and clear blue lake, where visitors can swim.
The open space, the echoing sounds of laughter as if someone is joking with you.
The camping spot for the journey is the sand beach of Hang En.
Photo suggestions for day 1: Sand region, camping, and blue lake.
Day 2: From Hang En to Ho Lun 1 (Sinkhole 1) in Son Doong Cave
Continue climbing hills and wading streams for the journey. Today’s most challenging point is entering the mouth of Son Doong Cave to get to the stop. Visitors carefully climb step by step on the wet and slippery rocks and follow the enthusiastic instructions of the support team.
The campsite at Ho Lun 1 is right inside Son Doong Cave, which also has a sandy region and lake like Hang En, but it is darker here.
Suggested photography for today: The point is before leaving the Hang En mouth for a standard camera and a few other spots in Son Doong Cave for professional cameras because of the dark light, including the stone top like the dog’s hand.
Day 3: From Ho Lun 1 to Ho Lun 2 in Son Doong Cave
Continue the journey to climb each precarious limestone slab. Slowly, we walk on the small trail that spreads between the thin vegetation on the cliff, and a breathtaking, enchanting scene opens up.
The cave ceiling is high, and the light from the natural gaps shines, creating shimmering, magical beams of light like in a fairy tale.
In the distance, an underground river flows quietly, reflecting natural light, blending with the humid, cool atmosphere, turning the cave into a different world, both pristine and mysterious.
The camping spot for day 3 is at Ho Lun 2 in Son Doong Cave.
Photo suggestions: Hang Tron (Circle Cave), where you can pose, the Garden of Eden, and fossil stairs.
Day 4: Crossing the stalactite wall to get out of the cave
Today was considered one of the most challenging days of the journey. Travelers will row in the dark for about 700 meters and cross the stalactite wall, named the Vietnam Wall, right at the cave exit.
The smooth stalactite wall has a vertical height of 25 meters and an average overall slope of 50 to 60 meters. Crossing this wall is difficult for most visitors participating in the Son Doong Cave tour.
The back cave entrance is about 500 meters away from the stalactite wall with a faint light. Here, you can come to the spot to catch a bus back to the hotel.
Suggested photos for day 4: The stalactite wall and the underground river where you row a boat.
5. Important notes when exploring
5.1. Before joining the exploration tour:
You must prepare your physical strength well enough to go to the forest, climb cliffs, and wade through streams for 4 days. A medical check-up before joining the Son Doong tour is a mandatory condition.
Walking about 10 km/day for 3 to 6 months prepares your physical strength. A preliminary self-assessment of your health by climbing stairs for 10 floors without affecting your health is the first condition when you can be ready for this journey.
To gain experience with this form of nature exploration, you should join more leisurely forest tours lasting 1 to 2 days. You should also visit some caves to get used to the high temperature, humidity, and darkness in the caves. This traveling preparation will make it easier for you to fully explore the professional tropical forest tour.
5.2. During the tour:
Son Doong Cave is located in a nature reserve in Phong Nha – Ke Bang National Park, so there are strict regulations on protecting the environment, flora and fauna, and the ecosystem in the cave.
Therefore, visitors are not allowed to harm any species of flora or fauna or destroy the cave structures, stalactites, stalagmites, and gems.
When participating in this journey, you should consciously protect Son Doong for future generations. Come and have fun, leave only footprints, and take away the experience and beautiful photos.
5.3. Best time to visit Son Doong Cave:
The Son Doong Cave discovery program departs weekly from January to August every year when the dry season comes to Quang Binh Province. However, occasional rain showers during the journey add moisture to the forest and the path.
The best time to visit Son Doong is from mid-late February to early April when the weather is not too hot and the rainy season is over. The mild, cool air adds to the excitement of the tour.
6. Why is exploring Son Doong Cave popular?
The feeling of conquering nature on an adventurous journey, trekking through forests and wading streams to uncover the mysterious beauty of Son Doong, helps you live closer to nature.
Breathe in the fresh air and listen to the chirping sound of the mountains, temporarily away from urban traffic noise for a few days. This activity not only makes you more relaxed but also connects you with nature, making you more attached to the peace of creation.
In developing Vietnam tourism, Son Doong Cave contributes significantly to promoting the image of the country’s majestic mountains, forests, and mysterious caves.
Diversifying traveling services in Vietnam, which has not only a long history and cuisine but also a fantastic nature, helps to raise the country’s tourism level on the world tourism map.
By organizing adventure tours professionally, Oxalis Adventure has become one of the prominent faces in travel companies in Vietnam, contributing to promoting the country’s beauty to international friends.
7. FAQs
7.1. Can I join the Son Doong tour with another company when Oxalis is full?
Besides Oxalis Adventure, no company is allowed to organize this tour to explore Son Doong Cave in Vietnam.
Please be careful if there are any invitations or promises to organize this tour outside of Oxalis company.
7.2. How can I travel to Son Doong Cave from Hanoi?
The most convenient way to travel to Son Doong Cave from Hanoi is to take a flight from Noi Bai Airport to Dong Hoi Airport.
If you already booked a tour with Oxalis, you should tell them your flight details. Then, they will arrange a transfer from the airport to your homestay, where you will stay overnight before exploring Son Doong.
7.3. Why is the group size only 6-10 people for one departure?
The 4-day and 3-night journey to Son Doong is complex, requiring much preparation and service.
Limiting the number of people in the group and the frequency of departures of the groups is to ensure the smooth implementation of the trip and, at the same time, to limit the number of participants to protect the natural environment and ecosystem of this cave.
7.4. What are the food and nutrition issues in this tour?
The professional team of Oxalis company takes care of all cooking, food transportation, and food service to ensure nutrition for adventurous days in the forest.
7.5. What are the toilet issues?
The organizer has fully arranged toilets for visitors at each stop on the journey. The staff will ensure hygiene and protect the natural environment.
7.6. Do I have other options besides the Son Doong cave tour?
If you want to visit the Phong Nha – Ke Bang caves but do not have enough health or finances for the Son Doong tour, you can choose a shorter program. For example, explore Hang En Cave only, or even easier, explore Phong Nha Cave, Tien Son Cave, or Paradise Cave.
Phong Nha Ke Bang National Park is considered the kingdom of caves in Vietnam. You have many options for exploring the fantastic nature inside its limestone mountains.
8. Conclusion and opening points
Exploring Son Doong Cave is not only a way to admire the majestic beauty of one of the largest caves in the world but also a journey to challenge courage and help us overcome our limits.
This journey reminds us of the importance of appreciating every step. Mindfulness and attentiveness can lead to safety and success – not just in exploration but also in daily life and work.
Also, the Son Doong Cave discovery adds more color to adventurous tours in Vietnam, enhancing the experience value of the journey to beautiful nature.
What is waiting for the next expedition?
In 2019, diving experts in the UK, coordinated with Phong Nha Ke Bang National Park, explored the depth of the underground river in Son Dong Cave and made an important discovery: The underground river in Son Doong Cave is more than 90 meters deep and has a diverse underwater ecosystem. This depth is a mystery; it needs more in-depth exploration.
From that exploration, an initial conclusion was made that Son Doong Cave has a 3-layer ecosystem, including a dry cave system, a water cave with a flow, and a cave over 90 meters deep that is not yet well known. This secret door is waiting for you – the cave expert – to carry out.
