This has brought the total number of visitors to the world’s largest cave to 1,300 since tours were first available in 2013.
Last year, Son Doong welcomed more than 500 visitors, including 67 Vietnamese. Vietnam ranked third in the number of visitors, after the US and Australia.
An exclusive week-long adventurous tour of Son Doong Cave is billed as one of the world’s top trips.
The cave was named in the list of the top ten lifetime trips and has been praised by prestigious magazines, newspaper and website like The New York Times, Tripadvisor, National Geographic and the Huffington Post.
The magnificent cave has also been featured on the US television network ABC’s Good Morning America show; and the ambassadors of Australia, Sweden, Italy, the UK, the Czech Republic and Argentina have taken part in the weeklong expedition.
In a bid to promote Son Doong Cave and the world natural heritage - Phong Nha-Ke Bang National Park, and serve the demand of tourists, Quang Binh province has allowed the sole operator Oxalis Adventure Tours to arrange more tours from January-August, 2017.
According to Director of Oxalis Adventure Tours Nguyen A Chau, the company will operate sustainable tours to reduce the negative impacts on the landscape.
The company is expected to receive 600 tourists to explore the cave during the season in 2017, he added.
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.
Within its caverns lie a jungle and a river, and the cave is large enough to fit a 40-storey skyscraper inside. The cave was named the largest cave in the world by the British Cave Research Association.
Son Doong Cave tour offers a five-day and four-night service at the cost of VND66 million (roughly US$3,000) per person from January to August. Each tour requires more than 25 porters and cooks, a tour guide, two cave experts and two park rangers.