Vietnam’s Thien Duong: longest dry cave in Asia and its stunning beauty - no wonder it’s name means paradise
- Thien Duong in the Phong Nha-Ke Bang National Park was formed 350 to 400 million years ago. It was discovered in 2005, and opened to visitors in 2010
- Only 15 visitors per day are allowed to explore up to 7km of the 31.5km-long cave, which is filled with stalactites and stalagmites of all sizes
We are making our way through Paradise Cave in central Vietnam, the longest dry cave in Asia, when our guide tells us to turn off our head torches.
“We are going to try walking in total darkness,” he says, as if exploring a cave formed 350 to 400 million years ago isn’t exciting enough already. I exchange a glance with my five tour mates, a family from England. The cave is relatively big and the walls are at a safe distance from us, but the thought of walking without lights is still daunting.
Wandering in the dark, with nothing but the sound of our footsteps echoing to accompany us, I take tentative baby steps and lag far behind until we finally turn our lights back on.
Paradise Cave one of the most popular caves in Phong Nha-Ke Bang National Park. It was discovered by a local who was hunting in the region in 2005, and its doors were opened to visitors in 2010.
The British Cave Research Association, which explored the cave, named it Thien Duong – Paradise – because of its beauty, and its walkways show off rotund and fluidly shaped stalactites and stalagmites of various sizes.
The first 1.5 kilometres (1 mile) is open to all visitors. The members of our group are among only 15 visitors allowed each day to explore up to 7km of the 31.5km-long cave, which extends all the way to the neighbouring country of Laos.
It is a trek that takes us through pristine parts of the cave, and which ends in a grotto illuminated by a collapsed cave roof known as a doline. The association discovered the doline in 2005 while exploring inside the cave, but it took a lot longer to find its opening in the thick jungle.
The first 1.5km of the trek are well lit, and the first 4km is easy. During the wet season, the hike often has to stop at the 4km mark because of high water levels. The next 3km involves some climbing, and at one point our guide and porter use their feet to anchor themselves and help us cross a tricky patch.
We finally arrive just before noon at the edge of a cliff that overlooks the doline, and listen to the sound of a rushing river below. We settle down to eat the picnic lunch our porter has been carrying.
The sunlight streams down, casting a perfectly circular strand of light on the cave floor far below. It is mesmerising to watch the shifting light in the cave as the sun moves across the sky or is obscured behind clouds.
After our picnic lunch, we journey back the same way we came.
The rock in this region is Mesozoic tropical limestone, deformed 400 million years ago in the Paleozoic era by tectonic movement to form mountains.
Being a calcite rock, limestone is highly soluble. The underground river, and millions of years of rainfall, have created oddly shaped limestone walls. Stalactites and stalagmites as old as the cave itself can be seen throughout our trek, forming columns where they have joined.
Our guide points out fossils of crinoids (coral stems) in the walls, and folded hollow columns that make a musical sound when tapped.
The underground river in the cave is at its lowest and we only have to wade through calf-deep water once. The still water is a crystal deep turquoise; to our surprise, we spot a fish darting in one of the pools. The cave is also home to crickets and scorpions.
The Paradise Cave trek is unlike any other I have done, and while the highlight is undoubtedly the doline, the walk there has been like immersing ourselves in an alien world.
Getting there
The nearest airport to Phong Nha is Dong Hoi Airport, which is an hour’s drive away. Most visitors either take the train to Dong Hoi then change to a bus, or get a direct bus from Hue, which is four hours away. There are also night buses to Ninh Binh, Hoi An, and Hanoi.
How to book
When to go
The hike can be done all year round; however, whether you will be able to reach the doline depends on the water level in the cave. The best time to visit is during the dry season from February to August.
