Son Doong Cave in Vietnam was first discovered in 1991 by a local man named Ho-Khanh, however, it didn’t become internationally known until 2009 after a group of British scientists conducted a survey of it.
The largest chamber inside the cave is 5 kilometres long, 200 metres high and 150 metres wide. These dimension meant that it overtook Deer Cave in Malaysia as the largest cave in the world.
In 2013 tourist expeditions through the cave began to go on sale for $3,000 per person.
Largest Cave In The World