Photo: National Geographic

According to Mr. Nguyen Van Ky, Deputy Director of the Quang Binh provincial Department of Culture, Sports and Tourism, each tour to Son Doong Cave will last for seven days and six nights at a cost of 3,000 USD.

Due to adventurous nature of the trips, each travel company is permitted to organize four tours per month and each of the tours will include at most eight visitors assisted by tens of tourism workers, he said.

Apart from Son Doong tours, Quang Binh province has also designed others in Phong Nha - Ke Bang National Park such as Rao Thuong-Swallow Cave, Dark Cave-Mooc Water Spring, Sinh Ton Valley-Aquarium Cave, Tu Lan Cave and Va Cave.

Son Doong Cave, which was created 2 to 5 million years ago by river water eroding away the limestone underneath the mountain, was first discovered in Phong Nha-Ke Bang National Park by a local man, named Ho Khanh, in 1991 and later made public in 2009 by a group of British scientists from the British Cave Research Association after their surveying trip in the park.

Only from August last year, tourists have been permitted to visit the cave. Since then, it has made headlines in prestigious magazines and on television channels, including in the National Geographic in 2011.

Son Doong Cave is more than 200 meters wide, 150 meters high and at least 6.5 kilometres long. Its largest chamber have enough space to fit 40-storey skyscrapers inside them.

www.quangbinh.gov.vn