The world's largest cave spanning over an incredible five miles long

The world’s largest cave is over five miles long - so big that even a Boeing 747 could fit inside it. Hang Son Doong is in Phong Nha-Ke Bang National Park in Vietnam, near the border with Laos and is the world's largest natural cave. 

It has a fast-flowing subterranean river and is the largest cave passage worldwide by volume. The cavern is 503 metres in height, 175 metres in width, and 5.8 miles long. The cave's interior is so large that it could fit an entire New York block inside, including skyscrapers, or could have a Boeing 747 fly through it without its wings touching either side. It is believed to be between two and five million years old and contains some of the tallest known stalagmites in the world, which are up to 80 metres tall.

Wildlife sightings are common, from monkeys, flying foxes, snakes, bats and birds to endemic species of fish, shrimp and creepy crawlies.

Hang Son Doong’s name is translated from Vietnamese as "cave of the mountain behind Doong". Doong is the name of a Van Kieu village.

The cave was discovered in the dense forests of Vietnam’s Phong Nha-Ke Bang National Park in 1990 by a local man, Ho Khanh, as he was seeking shelter from a storm. 

The cave then lay forgotten until Khanh led British caver Howard Limbert and his team there in 2009 to map Hang Son Doong for the first time.

Adventure tour agency Oxalis now offers multi-day exploration tours of Hang Son Doong. They take groups of ten into the caves for three days and four nights at £2,300 per person., 

Groups set up camp in the spectacular Hang En cave en route, taking a swim in a subterranean lake before descending into Hang Son Doong using safety harnesses.