Australian photographer John Spies, 59, who is owner of the famous Cave Lodge hotel in Thailand, spent a week photographing the natural wonder and the tourists flocking to marvel at its beauty.
Son Doong cave is hidden in rugged Phong Nha-Ke Bang National Park in the central province of Quang Binh near the border with Laos, the cave is part of a network of about 150 caves.
The cave is more than 200 meters wide, 150 meters high, and approx nine kilometers long, with caverns big enough to fit an entire city street inside them. It was first found by a local man named Ho Khanh in 1991 and was recently rediscovered in 2009 by British cavers, led by Howard Limbert.
The Telegraph reports that these breathtaking images capture the hidden depth of the world's biggest cave passage - so large that the end is yet to be found.
To get a sense of the enormity of the cave, it’s as wide as two football pitches and slightly longer than the distance of Buckingham Palace to the Olympic Park, it reveals.