In News on Tuesday 19th Jun, 2018

The cave that’s so big it could fit an entire New York City block of 40-storey skyscrapers

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A small part of Son Doong in Vietnam – one of the largest caves in the world. Source: Ryan Deboodt

Here’s one for all of the hardcore adventurers out there – or people who just love a truly amazing story.

In Vietnam there's cave that's almost 9 kilometres long and, in parts, reaches up to 200 metres high and 160 metres wide. To put it another way, it's big enough to fit an entire New York City block complete with 40-storey skyscrapers. 

Son Doong cave is located in the UNESCO World Heritage Site of Phong Nha-Kẻ Bàng National Park, on the country’s north-central coast. It is – unsurprisingly – one of the largest caves in the world.

Sunbeams in Hang En Cave. Source: Ryan-Deboodt
Sunbeams in Hang En, one of the smaller caves near Son Doong. Source: Ryan-Deboodt

The cave is nearly three million years old, but was only explored for the first time in 2009. Members of the British Cave Research Association had been trying to find the cave entrance for years and were eventually led there by a local man. Ho Khanh had discovered the entrance some 20-odd years earlier, but was unable to enter as the drop was too steep.

These days, the cave is accessible to a limited number of visitors every year – who must rappel/abseil down 80 metres to enter it. What they find when they get there is truly astonishing.

Son Doong Cave. Source: Ryan Deboodt
Son Doong Cave. Source: Ryan Deboodt

Hundreds of thousands of years ago the cave roof of Son Doong collapsed, creating two gigantic skylights (a.k.a dolines). 

The natural sunlight that these dolines allow into the cave has helped to give life to a dense virgin jungle, with trees, palms and ferns taking root almost 200 metres beneath the surface of the Earth.

Monkeys, flying foxes and a host of animals not normally found below the Earth live in the cave, thanks to the large plants that grow here and are able to support the wildlife – some trees are more than 30 metres tall.

The river inside Son Doong Cave. Source: Ryan Deboodt
The river inside Son Doong Cave. Source: Ryan Deboodt

The cave system is so huge it has its own climate, and mist and clouds form inside the cave and rise up to the dolines. Spectacular sunbeams also shine down through the dolines at certain times of the year – the spectacular effects of these phenomena are part of what makes Son Doong so special. And such a mecca for photographers.

A large underground river also flows within Son Doong Cave (which, in English, means “Cave of the Mountain River”). There's also a tranquil lake to row across. At the end, visitors can now exit the cave by climbing – with ropes and safety harnesses – a 90m-high calcite wall, known as 'The Great Wall of Vietnam'. It's a new part of the adventure that's only recently become available.

Climbing up the Great Wall of Vietnam in the cave. Source: Ryan Deboodt
Climbing up the 'Great Wall of Vietnam' in the cave. Source: Ryan Deboodt

Adventure tours began in 2013, and continue to this day, with only 1,000 visitors allowed into the caves each year, from February to August.

Adventure travel company Oxalis is the only company with the rights to conduct the tours. They have been working with photographer Ryan Deboodt to present these new photographs of this extraordinary cave – nothing similar has been published previously.

Son Doong Cave xxxxx. Source: Ryan Deboodt
Algae from ancient pools blankets parts of the cave. Source: Ryan Deboodt

Excitingly, Oxalis has also just released photographs and video footage of other caves in the region – look out for a future story on Hang Va, Tu Lan and Hang Tien caves.

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