Only 1,000 visitors are allowed into the caves each year, with each tour taking four days and three nights It is the largest known cave passage in the world by volume, which was found in 1990 and only fully explored in the last few years, can be seen by tourists.

Only 1,000 visitors are allowed into the caves each year, with each tour taking four days and three nights, and costing £2,245.

Those that sign up are rewarded with the chance to experience a cave so big it has its own weather system. At its tallest point the cave can accommodate a 40-storey skyscraper, while at its widest point there’s room to fly a Boeing 747.

Three photos of the cave system in Quang Binh province, including a photo of terraced stone system in Son Doong cave, are among the top eight most beautiful cave pictures in the world selected by well-known National Geographic.

As scheduled, in the second quarter of 2019, the province will carry out a program to explore a 600m-long underwater pathway that has never been discovered inside Son Doong cave to find a way to connect to a nearby cave (Thung cave).

In addition, the Animal Planet and the National Geographic TV channels will also join hand with Oxalis Adventure Tours to carry out thematic programs about Son Doong Cave and Phong Nha - Ke Bang National Park in 2019.

Source: VGP