As many as 360 domestic and foreign tourists have registered for a tour to explore Son Doong, the largest natural cave in the world, in the central province of Quang Binh in 2017.
The Son Doong Expedition Tour 2017 has been sold on the website of Oxalis Adventure Tours - the sole operator - at a cost of US$3,000 per person. The five-day and four-night tour is available for a maximum of ten people during January-August.
Tourists will have to cross over 50km of mountain and forest, with complex terrain, steep slopes, deep gorges, and wide rivers. Therefore, they must use supporting tools to overcome these challenges.
Most impressively, participants will take on a thrilling zip line to pass a path of over 80m to enter the cave.
This is considered the most adventurous tour in Quang Binh at present. The tour requires a team of 22 porters and two cooks, five safety assistants, one cave expert, a tour guide, and two forest rangers.
Son Doong Cave is more than 200m wide, 150m high, and approximately 9km long. It was believed to be formed 2-5 million years ago and discovered by a local resident in 1991.
In 2009, scientists from the British Cave Research Association prepared the cave for limited public access after surveying the area.
Its caverns lie in a jungle and a river, and the cave is large enough to fit a 40-storey skyscraper inside. It was named the largest cave in the world by the British Cave Research Association.
After three years of operation, the Son Doong Expedition Tour has attracted 1,300 tourists. More 600 visitors are expected to register for the adventure in 2017.