The Largest Cave, Son Doong: Dilemma of a World Heritage

And why we should stay on the side of conservation

By: Huong Nguyen Thien Le


The largest cave known to date is Sơn Đoòng, in Phong Nha – Kẻ Bàng – a National Park of Vietnam and  World Heritage of UNESCO. Twice the size of the second largest cave, this underground kingdom can house a whole block of New York City skyscrapers. The cave is so big it has its own weather, landscape, and ecosystem with jungles, waterfalls, rivers, and hills,  and is home to many rare flora and fauna species. Trekking inside it makes you feel like you are living in Jules Verne’s science-fiction novel, “Journey to the Center of the Earth.”

This 5-million-year-old hidden wonder was just recently discovered, with the entrance found in 1990 by local farmer Hồ Khanh and cave officially explored in 2009 by a British expedition team led by Dr. Howard Limbert. But like any other wonder found by humankind, the cave is facing the threat of being exploited. As it often goes, once people stumble upon a beauty, they find ways to make money from it.

Now, before we bash others for so doing, let’s take a moment to put ourselves in their shoes. Vietnam is a developing nation with a GDP per capita, PPP at about $6000. Quảng Bình province, where Sơn Đoòng is located, is one of the poorest provinces in the country. It shouldn’t surprise anyone that some of the provincial officers are attempting to commercialize the cave. And of course, the fastest way to milk the cow is mass tourism.

A cable car project, proposed by some of the largest domestic construction conglomerates, is being considered, which can bring in up to 1000 tourists an hour (equivalent to 1-1.5 million per year). That is a huge increase in tourism traffic, given the current trekking permit quota to this cave is only 1000 a year. However, Sơn Đoòng is not a cash cow, and should not be treated like one.

Biologically, cave ecosystems are very delicate because they are isolated from the outside world; let alone Sơn Đoòng, the underground world where no human beings had set foot in for five million years until 2009. In the unlit portions of the cave, the albino and sightless species have adapted to life without light for generations. German biologist Anette Becher commented, “Here in Son Doong, we are only beginning to scratch the surface of the biodiversity that may lie here waiting to be discovered.” The surge in an amount of visitors can inflict serious harm to the cave, due to the lighting, noise and carbon dioxide acidic breath adding further to the corrosion that naturally occurs.

Geologically, major construction into or nearby the cave can destroy its delicate structure. Associate Professor, Dr. Tạ Hòa Phương (President of Vietnam Association for Paleontology and Stratigraphy) and geomorphologist Vũ Lê Phương (Vietnam Academy of Science and Technology) both expressed serious concerns over the cable car project as Sơn Đoòng was formed on a series of strike-slip faults trending NW-SE. It has two dolines which are areas where the ceiling of the cave collapsed. A cable car system may trigger more destruction, which  not only threatens the cave itself but also put the lives of thousands of tourists in danger.

But no mass tourism means either zero tourists (like Lechuguilla Cave in the Carlsbad Caverns, where access is restricted for scientific research only), or a fairly selective system. Since closing off the cave completely is out of the question given the economic context of the province, the latter makes more sense. The only present way to explore Sơn Đoòng is trekking, which costs $3000 and requires a certain level of fitness. In other words, with the selective system in place, the two things that inhibit people from going are the price tag and physical requirements. With Vietnam’s average annual income mentioned above, this poses another problem: the wonder is only reserved for the well-off. A number of Vietnamese complain that they will never be able to afford to visit a World Heritage right on their homeland.

Two philosophy questions come to mind: Who does Sơn Đoòng belong to really? And what is the true value of Sơn Đoòng anyway? Many people just want to visit the place because of its title, the world’s largest cave. Those “most’s” – largest, longest, highest, etc. – attract common tourists. They come just to snap a selfie for their social media and brag with their friends that they’ve been to this “whatever-most.” They don’t care whether their five-minutes of fame may ruin a five-million-year masterpiece of Mother Nature. Would Sơn Đoòng still be spectacular with only its size and without its plant and animal residents? Sơn Đoòng might be forever the world’s largest cave; but it will be just a hollow chamber once its pristine charm is destroyed.

U.S. Ambassador to Vietnam, Ted Osius, turns our attention to the second part of Sơn Đoòng’s title, a “World Heritage”. The name suggests two things: (1) “These are sites that are considered to be not just of interest to the people in the countries where they’re located, but of interest to the whole world”; and (2) heritage doesn’t just belong to this generation, but our before and after too. For those who are concerned about the intra-generation social injustice (that only a number of people get to visit this beauty), think of the inter-generation social injustice: If you fail to preserve this heritage site, you’re depriving the future generation of the right to enjoy it. And these two ideas (that World Heritage sites should be preserved for the World and for the future) are not just personal opinions, but in fact stated in the laws by (1) Point 1, Article 6, Chapter II of the Convention concerning the Protection of World Cultural and Natural Heritage and (2) the Sustainable Development Goals (for the case of Phong Nha – Kẻ Bàng, it is goal #15) – both of which Vietnam has signed on to. Let’s remind ourselves of what President Obama said during his trip to Vietnam last year: “”Natural wonders like Ha Long Bay and Son Doong Cave have to be preserved for our children and our grandchildren.”

Environmental Law Professor, Joseph Sax – a self-claimed preservationist – wrote in his book “Mountains Without Handrails” that some areas should be saved explicitly for “contemplative recreation,” where “people can be encouraged to use their leisure time in a slower-paced, less energy-consuming, and more intensive fashion.”  This approach is ideal for Sơn Đoòng – a place that is described by Tourism Professor Nguyễn Thu Thủy (Vietnam National University, Ha Noi) “an unreal world”; or Dr. Đặng Hoàng Giang (VP of Center for Community Support Development Studies) a place where he “had the feeling that [he] was going to meet the Creator” and “it made [him] so small and so insignificant.”

Take a step out of the philosophy world, even economists would agree with these ideologies. The Exxon Valdez Oil Spill in 1989 sets a precedent of our environment’s non-use values being officially recognized by the U.S. Federal Government: The incident did not only harm Alaskans economically, but also affected all Americans as it destroyed one of the nation’s most untouched marine conditions. In the case of Sơn Đoòng, the cave has values even in non-use forms – in economic terms: Option value (value for potential use), Bequest value (value for future generations), and Existence value (value for those of us who will never be able to visit it, but who are still happy knowing it is there). Or in layman’s terms, money can be earned, fitness can be trained, but damage to such a natural wonder is irreversible. This is also agreed with by Deb Limbert (British Cave Research Association), “Caves are fragile environments. […] Once they’re broken, they’re broken.”

Back to the cable car story, a group of young Vietnamese activists, myself included, have been campaigning against mass tourism and advocating for the conservation of Sơn Đoòng for the past three years. Our #SaveSonDoong team has built a loyal fan base of more than 175,000 followers, established our online presence, and organized numerous offline events, from movie screening, photo exhibition, to workshops, conferences, debate forums, competitions, etc, including meeting President Obama. Moving forward, we want to solve the above unjust issue by exhibiting 360-degree videography of the cave, a project in collaboration with RYOT News and photographer Jason Speth. This will bring the beauty of Sơn Đoòng to a lot more people while embedding the lessons about the scientific values of this World Heritage.

The project by no means aims to replace traditional traveling methods, but rather engage viewers to educate them and in returns produce more informed travelers. Our theory of change is that most harmful actions are caused by lack of knowledge, rather than bad intentions. So the stunning VR footage of the cave can be a powerful “edutainment” tool. And we cannot wait for the first high-tech traveling exhibition to be launched in Vietnam.

In a nutshell, Sơn Đoòng is not suitable for mass tourism because of a wide range of reasons, from ecology, to geology, to economics, and even philosophy. All of these disciplines still hold a very anthropocentric view, regarding mankind the central of the universe – as if everything was created to serve us. This hidden treasure was formed even prior to human race, though I guess we still have a long way to go on our moral growth before we can talk about nature rights. The dilemma between economic development and environmental conservation is a classic tension and might still be one for many more decades to come. But with the rise of technology, it is reasonable for us to have faith that eventually there will be a day when we all can enjoy nature, without destroying nature.


To support the #SaveSonDoong campaign, please click here.


Photos by: Karen Masumoto


Photo by: Tarik Benbrahim


Photo by: Tarik Benbrahim


Photo by: Tarik Benbrahim


Photos by: Jason Speth


Photos by: Jason Speth


Photos by: Jason Speth


Photo by: Jason Speth


Photo by: Jason Speth

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Photos by: Jason Speth


Photo by: Jason Speth


Photo by: Jason Speth

Header Photo by: Jason Speth


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