#Fernweh: Hang Son Doong in Vietnam

Hang Son Doong is world’s largest cave. It has its own jungle, its own climate and is 200 meters high, twice as high as the Statue of Liberty. The cave Son Doong (in Vietnamese “Hang Sơn Đoòng”) literally hides in the middle of the national park Phong Nha-Kẻ Bàng in Vietnam at the border with Laos. It is part of a network of hundreds of caves, many of which are still unexplored.

It is located in the center of Vietnam, in the Phong Nha-Ke Bang National Park. Only 50km away from Dong Hoi, the capital of the central Vietnamese province of Quang Binh. It is the largest known cave in the world and around it there is a whole cave system with around 150 other caves – including the third largest cave in the world, the Hang En. Nevertheless the Hang Son Doong and the cave system around it has only been discovered in 1991. The cave was found by a local man named Hồ Khanh. The whistling sound of wind and roar of a rushing stream in the cave heard through the entrance as well as the steep descent prevented the local people from entering the cave.The entrance to the cave is a 80m deep canyon, the “discovery” did not really bear fruits until much later. It took another 18 years until the cave was finally explored by British researchers in 2009. And since 2013, it has been open to visitors. To this day, there were fewer people in the Hang Son Doong than on the summit of Mount Everest!

The Son Doong cave has a height of 250m, a width of 150m and a length of 5km and is thus so large that a Boeing 747 could easily fly through the cavern or fit a 40-storey skyscraper. What makes the Hang Son Doong unique in addition to its size are two openings – a kind of window if you will- upwards through which sunlight enters the cave. Under these two windows are real jungles with trees up to 30m high and through the whole cave flows a river and there are several smaller and larger lakes. The age of the caves is estimated to be two to five million years. In the Hang Son Doong and many of the other caves are also flying foxes, basically a giant bat. These huge bats reach a wingspan of more than 1.5m.

The only provider with whom one can make tours of the cave system is Oxalis. Oxalis offers various tours through the Hang Son Doong and also tours to some other caves at the Phong Nha-Ke Bang National Park. The tours are sorted into different fitness and “adventure levels”, from Level 1 for people who can walk 60-120 minutes on flat, partially rocky ground up to level 6. There you have to embark on 50km on trekking trails in 5 days , 40 river crossings and so on. For this level it is assumed that you have plenty of experience of trekking tours. Unfortunately, the only tour that goes straight through the whole Hang Son Doong is a level 6 tour. The price of the tour is approximately $3,000 per person, not including travel to and from the cave. In small teams of up to 8 guests, visitors will trek deep into the remote jungle of Phong Nha Ke Bang National Park, cross stunning river valleys, and witness the incredible cave formations. A team of 16 porters, safety experts, and guides will accompany guests on the six day adventure. The tour to Son Doong Cave begins 35km within the national park, where guests will trek the 6km to arrive at the camp inside Hang En. Early the next morning, travel through this enormous cave to reach its amazing exit and then follow the river to the entrance of Hang Son Doong.

The caves around the Hang Son Doong are very similar in their climate. Through the rock formations and by the river, the caves are usually connected with Hang Son Doong. The whole cave system is so mesmerising that it forces you to question whether you are still on this planet at all. Foreign landscapes found nowhere else, enormous stalagmites rising from the ground and statuesque stalactites hanging from the ceiling like an alien species. Inside the gigantic cave is also a local weather system that even misty clouds form to make the whole thing even more mysterious.

In an attempt to limit protect the delicate ecosystem, only 800 visitors are allowed to enter in a given year. Oxalis’ 2017 tours were sold out in only 20 hours after the posting. Eager explorers will now have to wait until next year to even see the 2018 dates.

Images by National Geographic