The enormous cave is situated in the Vietnamese national park Phon Nha-Ke Bang, 280 miles south from the countries capital city Hanoi.
Son Goong means ”mountain-river-cave” and crafts from two too five million years ago. But for a long time it was undiscovered. It was first found in 1991 by a local farmer, but the first people who explored the cave was brittish experts in 2009.
The cave as a whole is considered to be 87 miles long.
It contains its own animal life, a rainforest, lakes, beaches and a river.
A lot of caves has relics from a prehistoric age, like statues or paintings in the mountain walls. But nothing like that has been found in this cave.
2013 did the first tourists visit the cave.
There are guided tours to get here. The tour can take seven days and the cost is around $2300 (1500 brittish pound). For that price you will also spend five nights camping inside the cave.
The cave is also rich in rare pearls that has been shaped for centuries by water drops that’s been dried and shaped a layer of lime on the sand.