It has room for a skyscraper with 40 floors and it contains both jungle and a river. The Son Doong cave in Vietnam is the largest in the world and a tour inside it is something quite out of the ordinary.
Tag along in this underground world and be astounded by how beautiful nature can be.
The enormous cave is situated in the Vietnamese national park Phon Nha-Ke Bang, 280 miles south of the capital Hanoi.
Son Goong means ”mountain-river-cave” and crafts from two to five million years ago. But for a long time it was undiscovered. It was first found 1991 by a local farmer, but the first people who explored the cave were British 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 on the mountain walls. But nothing like that has been found in this cave.
In 2013 the first tourists visited the cave.
There are guided tours to get here. The tour can take seven days and the cost is around $2,300 (£1,500). For that price you also spend five nights camping inside the cave.
The cave is also rich in rare pearls that have been shaped for centuries by water drops that’s been dried and shaped a layer of lime on the sand.