On arrival in Phong Nha, the group of Brits found munitions piles, old weapons and unexploded ordnance of the US Military (UXO’s) piled up in the front yards of the villager’s huts. They were being sold as scrap metal. There was one brick building in the town, which they found to be a makeshift village hall. This was their home for the following 9 days; the cavers are by nature a resilient breed and they thrive on uncomfortable travel adventures.

Upon settling in, they proceeded to explore what are now known as Phong Nha Cave and Dark Cave (Hang Toi). Three from the team delved over 8km into Phong Nha Cave and to this day nobody has been back in that far. Howard Limbert, who was on the expedition, likes to say: “less people have been to the end of Phong Nha Cave, than people have been to the moon”, although 100,000’s of tourists now visit the first 1km of the cave every year. The group that went right through the length of the Dark Cave found some enormous caverns deep in the cave and some that are located and begin in the area of what is now known as the Abandoned Valley. All of these caves and areas are now visited daily by tourists visiting Phong Nha Ke-Bang National Park.

Around the same time in 1990, as this expedition was taking place in some of the easier to access caves on the edge of the Karst Massif that now makes up the Phong Nha Ke-Bang Unesco World Heritage area, a young 16 year old local boy named Ho Khanh was hunting with family members deep in the more recently labelled “core zone” of the park. At that time, it was a good 20km trek through dense jungle in this relatively unexplored region of the planet, over treacherous mountains shielded by sharp weathered limestone.

Ho Khanh was separated from the rest of the group, and when a thunderstorm passed he found shelter under an overhanging cliff. When the weather cleared, he noticed what seemed to be clouds bellowing out from the side of the mountain, not even 20m away from where he was stationed. On closer inspection, Ho Khanh found a cave entrance that upon entering by 10 meters saw that the floor dramatically fell away in a sheer cliff, into what seemed like the depths of a dark abyss of nothingness below. Ho Khanh left the cave and sought out to find the rest of the hunting party and continued with his day-to-day life.

In 1994, the Vom Cave System was extensively explored and Paradise Cave visited everyday now by tourists is part of said Vom Cave System, with its labyrinth being physically the longest cave in Vietnam. In 2005 the entrance to Paradise Cave was located from the outside by a local man named Phuong. Mr Phuong happens to be Ho Khanh’s brother-in-law. The families of exceptional experienced jungle men all live at the western end of Phong Nha Village, where Ho Khanh and many of the other local families now operate really cool little homestay accommodations for the increasing amount of visitors to the area.

Fast-forward around a decade to 2005 at which time Ho Khanh was introduced to the now locally seasoned Howard and Deb and the other British cavers who had been caving here every other year or so since the first expedition in 1990. Ho Khanh met Howard and Deb’s group in 2003 and told them that he knew of many caves and seen the many cave entrances over decades of growing up and hunting in the local Jungle. He hadn’t explored them, but this didn’t surprise the Limbert’s or their exploring companions as this was a normal situation for the local people. They tended to avoid going beyond the entrance to the caves in the region. There were some exceptions, like Hang En Cave which was used by the Ban Doong minority tribe as a thoroughfare and Phong Nha Cave and Hang Rou which were used during the war for storage and the production of rice wine respectively. Prior to around 2005 the local people here didn’t have flashlights so the darkness of the caves were hard to navigate and besides, it was a widespread superstition of the local people that caves harboured spirits.

Khanh continued to tell the British cavers about the cloudy cave entrance he discovered when he was seeking shelter whilst hunting as a young boy, located just after and above the waterways of Hang En and Hang Curry converge. Khanh, couldn’t remember the exact location but agreed he’d try to find it for a future expedition. In 2009 an expedition was officially organised and led by Howard and Deb Limbert, to explore in this area beyond Hang En and over the mountains, past the dolines of Hang Son Doong, finishing to the north on the National Park’s rugged core zone on Highway 20 somewhere between Hang Tam Co, 8 Ladies Cave and the “A Rem” Minority Village near the Laos border.

The cavers were guided by Khanh to the entrance of what he’d simply described as a cave he’d seen with clouds coming out. A caver named Adam Spillane was the first to enter. Just beyond the entrance it was found that the cavers would have to descend the steep cliff into the darkness. The group upon exploring some of the interior of the cave were completely breath taken by the sheer dimensions of the caverns found as they moved north, farther into the cave.

The plan to cross the mountains to Highway 20 was abolished and the rest of the time was spent exploring Hang Son Doong.

In 2010, the Cavers returned with the National Geographic magazine and TV team to further explore and map the cave. It was proven that by volume that Hang Son Doong is the largest Cave discovered in the world, outrunning Deer Cave in Malaysia, which previously held that distinction.