HO CHI MINH CITY -- Son Doong, the world's largest cave, is so vast that it has a self-contained climate and ecosystem. Located in Quang Binh, a province about 500km south of Hanoi, it has a massive roof formed millennia ago. The cave shelters a fast-flowing river, chambers, fossils, deep passageways, and some of the largest stalagmites and stalactites in the world.
In Phong Nha-Ke Bang National Park, a Unesco World Heritage site in the mountains of central Vietnam, Son Doong, or "Mountain River," cave is close to the border with Laos and not far from the Ho Chi Minh Trail, a jungle network used by communist forces during the Vietnam War.
Son Doong is one among approximately 150 natural grottos in the park. Phong Nha, which is only a fifth of Son Doong's size, was previously thought to be Vietnam's largest cave. The larger cave has underground rivers and waterfalls, which support a unique vegetation ecosystem. It is 9km long, more than 200 meters wide at its broadest point and 150 meters high. By comparison, Malaysia's Deer Cave, previously considered the world's largest, is 148 meters high and 142 meters wide.
According to Unesco, Phong Nha has "an impressive amount of evidence" of Earth's natural history, and is helping experts better understand the region's geology and evolution. The cave is a part of the oldest major karst formation in Asia. It dates from the Paleozoic era, more than 250 million years ago, when the first plants and animals developed.
Today, more and more tourists are visiting the park. But Son Doong itself is hard to reach. Gaining entry to the cave requires multiple permissions. This helps keep the cave in pristine condition. But some in the private sector want to make it more easily accessible to the public. Opponents of plans to open up the cave have taken to social media to make their voices heard, which some see as an example of Vietnam's slowly emerging civil society.
In 1991, Son Doong was discovered by a Vietnamese farmer named Ho Khanh, but awareness of it only really developed when a group of scientists from the British Cave Research Association, led by Howard and Deb Limbert, explored it in 2009 with Khanh's help.
Five-day expeditions to Son Doong started in 2014 that include a trek through Doong forest, a chance to meet indigenous people at Doong village and go caving in Hang En, which is nearby. In the depths of Son Doong itself, visitors see 70-meter stalactites and stalagmites, cross roaring underground rivers and learn from British experts.
Only about 230 visitors were allowed in during 2014, mainly from the U.S. and Australia. Oxalis Adventure Tours, which is headquartered in the park, operates the treks. The waiting list to visit the cave is long.
Experts from the British cave association have provided advice on safety and sustainability, and guidance on heritage issues. No more than 10 visitors are allowed in each group, accompanied by two caving experts, two forest protection officers, three local guides, and 25 local porters, who carry provisions for five days.
When their turn comes, visitors pay $3,000 to join the trek. The best time to visit is between January and August; underground rivers flood Son Doong's deep interior in winter.
This year, 500 visitor permits will be issued, generating $1.5 million in turnover. Of this, the national park collects 20%. The remainder goes to Oxalis, which must fund 50 tours and pay the trekking staff. In all, some 200 people are involved.
According to Khanh, the cave and other attractions have helped boost local household incomes by as much as 30% over the last five years. Some illegal loggers have found new work in tourism.
"We would like to see more visitors arriving in the future, said Khanh. "But we want our natural treasures protected better than Ha Long Bay, which was overexploited by unsustainable projects and out of control visitors." Ha Long in Quang Ninh Province, another Unesco World Heritage site, also has caves.
Quang Binh was the birthplace of Gen. Vo Nguyen Giap (1911-2013), Vietnam's most celebrated military commander. Giap's troops overcame the French at Dien Bien Phu in 1954 and outlasted U.S. and southern forces in the Vietnam War. Buried near his birthplace, Giap's grave attracts millions of visitors.
The province is one of the poorest regions in Vietnam. More than 70% of people there are low-income farmers, and education facilities are extremely limited. The huge cave's discovery could lead to more jobs and contribute to the province's economy. Provincial authorities initially appeared to accept the idea of limited financial turnover, but now want to cash in on tourism.
Although Oxalis has exclusive access to Son Doong, other companies run low pressure, sustainable tours in the vicinity. The monopoly will be difficult to protect, threatening the park's pristine condition. In October, Quang Binh authorities unveiled a proposal for a cable car system in the park that would open up Son Doong to mass tourism.
The developer, Sun Group, specializes in tourism-related projects and has surveyed the area. The company operates cable cars in other parts of Vietnam, sometimes controversially. Its 5km cable car from the port city of Danang up to Ba Na Hills, which houses a tourism complex, ran into problems. The group tried to block road access to the area and charge visitors $25 for cable car tickets. Locals argued the area was not the property of Sun Group and that the road should stay open. The locals won.
Sun Group's most ambitious proposal, however, is the 10.6km cable system that would make Son Doong easily accessible. The project includes a resort complex with accommodation, recreation facilities and shops. It could bring 1,000 visitors an hour to Son Doong, promoting Quang Binh as a tourism hub and generating "thousands of jobs for the poor local people," Sun Group said.
The tourism ministry has allowed Sun Group to do its preliminary survey. According to the developer, its "environmentally friendly" project has four components and requires investment of about $210 million. The initial plan was to bring visitors to the cave floor by lift. Local experts opposed this idea, however, because of the risk of the cave ceiling collapsing. The revised plan brings visitors in through the back of the cave, but this route is blocked after 300 meters by a 60-meter high expanse of calcite.
Locals and cave experts object to the plan, believing it will have a devastating environmental impact. Howard Limbert, head of the British exploration team that has worked in the Phong Nha-Ke Bang area for the past 24 years, advocates strict limits on the number of visitors to the cave. Its delicate ecosystem, he argues, would not survive if the cable car plan went ahead.
British and Vietnamese experts rejected the proposed cable car, saying the cave ecosystem would be destroyed like Ha Long's had been. Local people launched a "Save Son Doong" anti-cable car campaign, which has attracted thousands of followers on social media. There have also been workshops to discuss ways to protect the cave and ensure any development is sustainable. An online petition has garnered thousands of signatures and prompted Unesco to request a thorough environmental impact assessment. The international agency will send its own team to study Sun Group's development plan before making any recommendations on the cable car.
Some believe the possibility of being delisted as a Unesco World Heritage site might exert some sway in the final decision.
In February, Hanoi signed off on a regional development plan that essentially leaves the area unchanged. This should block the construction of a cable car to Son Doong for some years. But the longer term is less certain. A source familiar with Vietnamese bureaucracy told the Nikkei Asian Review the provincial authority gave a green light to the Sun Group project before it made the preliminary survey known.
Social media activists
The Son Doong cable car is not the only project in Vietnam raising concerns about sustainability. On Facebook, the platform many of Vietnam's 25 million members use to air their views, other debates are raging on projects some believe will be detrimental to the country.
In the north, a plan to replace nearly 7,000 ancient great trees along the streets of Hanoi triggered three demonstrations in a week. The trees survived the U.S. bombings and urban redevelopment schemes. The protests, organized on Facebook, led to the disciplining of officials involved in the project.
In the south, a 100-meter stretch of Dong Nai River was to be reclaimed for an urban redevelopment project in Bien Hoa, 50km north of Ho Chi Minh City. The project was suspended in March amid strong opposition. The Dong Nai, one of Vietnam's longest rivers, is a vital source of water for millions of people. Reclamation would have damaged the environment and created a bad precedent for future encroachment on waterways and natural drainage conduits, according to the Vietnam River Network, an open forum.
The social activism was reported to have begun with ordinary young people living around the province of Dong Nai and in Ho Chi Minh City. They had had no particular political, social or economic background that was discernible. As the Facebook pages attracted attention, more people from other parts of Vietnam became involved.
Vietnamese authorities and investors have suspended a number of projects to placate the public while proposals receive further scrutiny. Facebook fan pages have attracted thousands of hits and "likes" from a wide range of people, encouraging mainstream media to be critical of what would normally be considered sensitive issues. Links and articles have been shared, encouraging a broader debate on development problems in this densely populated and tightly controlled country. Foreign support has also been enlisted on occasions. Officials and executives may now find themselves penalized for hurried, ill-considered decisions on projects that fail to take into account local sentiment and are not backed by sound research.
At present, the processes for issuing permits and defining the rights of stakeholders are murky and susceptible to corruption. Powerful interest groups are known to be wrangling before the Communist Party of Vietnam's congress in 2016. The government makes key decisions at the congress, which takes place once every five years. Other problems include generally poor governance and communist Vietnam's inexperience with privatization.
"The growth of Vietnam currently produces five kinds of wastefulness: waste of capital, waste of natural resources, waste of foreign currency, waste of the environment and waste of culture," charged Truong Trong Nghia, a lawyer and congress delegate.
Rising social activism and stronger stands against unreasonable decisions by officials means to some that civil society has arrived in Vietnam. Pham Chi Dung, an economist and political commentator, believes the growing number of people prepared to stand up for what they believe in proves that civil society is emerging. Speaking out in the past would have invited the attention of state security.
"This has been a remarkable year for civil society in Vietnam," said Dung. Even though it is in early stages, social media has become more influential, and both central and local governments have had to take greater account of public opinion when making decisions.
Son Doong, it seems, has been a wake-up call for policymakers -- a bright warning light from a dark cave.