Discovered in 1991, Son Doong Cave, which is in Vietnam near the border with Laos, has been revealed to be the world’s largest known cave. The name means “Mountain River Cave” and it does have a large river running through it. In fact, the whistling sound of the river is hat has protected the cave, as locals were scared of the noise so stayed away from the area.
A British expedition finally explored the cave in 2009, and have confirmed that is, by far, the world’s largest known cave, dwarfing the former contender, Deer Cave in Malaysia.
The size of it is almost beyond belief. Son Doong cave is more than 200 metres wide, 150 metres high, and approximately 9 kilometres long, with caverns that are big enough to fit an entire city street, complete with 40-storey buildings, inside them. The cave is part of a network of 150 or so caves that are known to exist in the Annamite Mountains.
Part of the reason for the cave’s late discovery was because the entrance was hidden by dense jungle. When the cave was finally broached, the expedition party got several kilometres into the cave when they were stopped by a formation they called “The Great Wall of Vietnam”, which was a 60 metre-high cliff of muddy calcite.
Beyond the cliff is a massive chamber where the roof has fallen in and light enters the cave to reveal its true height. Estimates are that the cavern in this section has a height of 800 feet, and because the cave is located beneath a rain forest, the roof is so high that clouds form within the cave.
Also plentiful are cave pearls. These are formed by droplets of water falling from the ceiling. They form spheres around a speck of dirt, much like a pearl, and are usually just the size of a marble. In Som Doong Cave, these pearls reach the size of baseballs, which is probably due to the height from which they have fallen.
The caves are now open to the public, but they can only be visited on tours which are organised by government-approved operators. The cave visits are quite tough and suitable only for people who are quite fit. Nevertheless, the tours do offer adventurous folk the opportunity to see one of the world’s most wonderful natural attractions.
The Son Doong Cave experience is one which will surpass all expectations.