Bookings to Son Doong cave in the central province of Quang Binhare full for next year, according to Oxalis international travelcompany, which is permitted to pilot the adventure tour to the worldbiggest cave.
Four hundred tourists have booked tours to the cavenext year, at least 3,000 USD each. Six hundred tourists worldwidecontacted the company for the tour in 2015.
Son Doong cave wasfirst discovered in Phong Nha-Ke Bang National Park by a localman named Ho Khanh in 1991.
The cavewas then made known publicly in 2009 by a group of British scientistsfrom BCRA, led by Howard Limbert, after their surveying trip in thepark.
According to Limbert, the caveis five times larger than the nearby Phong Nha cave, previouslyconsidered to be the largest in Vietnam .
Son Doong cave is found to have a length of at least 6.5 kilometres.It is estimated to be 200 metres in width and 150 metres in height. Thelargest chamber of the cave is judged to be 250 metres in height.-VNA