This figure is still modest in comparison with visitors’ demand, however it generated a revenue of nearly 10 billion VND (nearly 470,000 USD) for Quang Binh province, the host locality of the cave.

At present, if visitors want to book the tour to explore Son Doong cave, they have to book it online. However, many visitors who have booked the tour for a long time, said they are still waiting for their turn to explore these natural masterpiece.

According to Mr. Nguyen Van Ky, Vice Director of the Quang Binh Department of Culture, Sport and Tourism, the tour is still on a trial basis, only four trips were organised a month with the maximum number of eight visitors for each trip.

In August this year, the province plans to review the trial tour’s efficiency, including its cost, in a bid to make the optimal plans for future exploratory activities.

During the trial period, each tour to Son Doong cave lasts for seven days and six nights at a cost of US$3,000 for each visitor.

Son Doong Cave's entrance was first discovered in the Phong Nha - Ke Bang National Park by a local man in 1991, and was later publicized in 2009 by a group of British scientists from the British Cave Research Association.

The scientists said that Son Doong Cave have been created two to five million years ago with river water eroding the limestone underneath the mountain.

It has a length of at least 6.5 kilometres and is estimated to be 200 metres in width and at least 150 metres in height. The largest chamber is an incredible 250 metres in height, enough space to accommodate 40-storey skyscrapers.

Recently, Sheikh Khalifa bin Zayed bin Sultan Al Nahyan, Crown Prince of Abu Dhabi, the capital of the United Arab Emirates, has completed a discovery trip to Son Doong cave which made a strong impression on him and fully satisfied his adventurous pursuits.

Reported by VietnamPlus
(www.quangbinh.gov.vn)