Couple from Bradford discover the world’s largest cave in Vietnam, which is 5.5miles long and could fit a 40-storey skyscraper in it

Son Doong, in Quang Binh, Vietnam, was discovered in 2009 by Howard and Deb Limbert from Bradford

They gave up jobs as biomedical scientists in the NHS to explore caves around the world



There is no record of humans visiting the underground forest

Tress up to 50 metres tall have flourished thanks to large entrances letting in sunlight


This is the jaw-dropping hidden utopia that a Bradford couple chanced upon on holiday.

The underground cave is showered with sunlight that pours through two huge entrances, allowing trees up to 50 metres tall to flourish.



Tucked behind a mountain in Vietnam, Son Doong - meaning river mountain - has sat peacefully under the human radar for as long as records can show.

Caves are defined as 'big enough for a human to fit inside'. Towering above its minuscule explorers, this cave has shocked nature experts.

Scroll down for video

Harold Limbert pictured at a massive entrance to the cave. Married couple Howard and Deb Limbert have opened up the amazing Son Doong cave, the largest cave in the world, to adventure tourists after discovering it in 2009 The couple heard about the cave from a local man who had taken shelter from a storm in the entrance to Son Doong, in the mountains of Quang Binh 20 years ago

The first public tour in August 2013 camps on the floor of the cave. Mr and Mrs Limbert were joined by six tourists, 16 porters, two UK guides, a Vietnamese English-speaking guide, two National Park rangers and a porter manager

Measuring 5.5 miles long, it is home to a lush green forest, cascading waterfalls, giant stalagmites and stalactites and a river. The cavern is so large, a 40-story skyscraper could fit within its walls.

The luscious underground forest is home to all sorts of cave-dwelling creatures from flying foxes to monkeys.

The cave was first explored in 2009 by Howard Limbert, 56, and his wife Deb, 53.

The couple, who met at a school caving club, took a gamble four years ago when they dropped their NHS jobs in Bradford to travel the world in search of new and exciting caves.

They heard about the cave from a local man, Ho Khanh, who had taken shelter from a storm in the entrance to Son Doong, in the mountains of Quang Binh in Vietnam 20 years ago.



Rare 'cave pearls', calcium formations, on the floor of the cave. Mr Limbert said: 'Son Doong is unlike any other cave on the planet. We were so lucky to have the chance of being the first people to see this new wonder of the world.'

He heard the sounds of a powerful river and rushing wind, but was too afraid to venture further in.

Mr Khanh told the Limberts about his discovery when he led them as a guide through the Vietnamese mountains in 2009.

Mr Limbert said: 'Son Doong is unlike any other cave on the planet.

'We were so lucky to have the chance of being the first people to see this new wonder of the world.

'It is always very exciting to explore somewhere where no one has ever visited, but to have the chance to explore Son Doong was very special indeed.'

Howard and Deb Limbert, in the foreground, look on as a tourgroup member explores the cave in the distance. The couple have been overwhelmed by requests to join expeditions into the world's largest cave and expect all 220 places on tours next year to be snapped up fast

Members of a tour party cross a river in the cave. The couple used to work for the NHS as biomedical scientists and spent most their holidays on caving expeditions

The couple, married for 34 years, relocated to Vietnam permanently and set up a business leading tour groups to the heart of the cave.

There have now been 25 specialised expeditions into Son Doong since the cave was first discovered.



And last month, in a groundbreaking adventure, Mr and Mrs Limbert led the first public tour.

Six tourists went on the first trip, accompanied by 16 porters, two UK guides, a Vietnamese English-speaking guide, two National Park rangers and a porter manager.

To enter Son Doong the group of international tourists from Britain, Australia, the USA and Norway, had to abseil down through the thick forest under the caves entrance.

Mr Limbert said: 'We have probably lived in the cave now for over four months in total.

'The tour is incredibly popular and all clients taken so far say it is the greatest adventure on the planet.'

The couple have been overwhelmed by requests to join expeditions into the world's largest cave and expect all 220 places on tours next year to be snapped up fast.

An expedition member in the cave. Records do not show any human activity in this underground world which could hold a 40-storey skyscraper

Harold Limbert pictured in one of the largest caverns in the cave. It has many compartments and species that the couple, who met in a caving club at school, have yet to discover. They have moved permanently to Vietnam to continue their exploration

The couple used to work for the NHS as biomedical scientists and spent most their holidays on caving expeditions.

Mr Limbert said: 'We have both been exploring caves for most of our adult life and it has enabled us to visit some wonderful places in the world and meet some fantastic people. We are lucky that we both have the same interest.

'We explored the caves of the UK during our first few years of caving and still continue to explore the fascinating caves of Britain.

'We caved in Europe and then later in Mexico, Borneo, Australia and New Zealand.

'We first visited Vietnam on a caving expedition in 1990 and now we have explored over 200m of new unexplored caves during the last 23 years of our work in the country.'

The intrepid couple believe there may be a larger cave for them to discover yet.

Mr Limbert said: 'We still believe that an even larger cave could be found in the remote mountains in central Vietnam.

'We are leading an expedition of British cavers in March and April next year to continue our work in the area and hopefully find another cave larger than Son Doong if that is possible.

'We have only explored around a quarter of the remote mountains and our guides have found many entrances for us to visit.

'Hopefully early next year we will have the chance to explore more amazing caves in the area.'