Phong Nha-Kẻ Bàng National Park is one of the world’s largest limestone regions with over 300 caves and grottoes. This area also contains the oldest karst mountains in Asia, formed approximately 400 million years ago. Below ground, the park is home to the world’s largest cave systems. Sơn Đoòng Cave, discovered in 1991 by a local man but not surveyed until 2009, is the largest known cave on Earth. This cave runs nine kilometers with chambers 200 meters high and 150 meters wide. Sơn Đoòng Cave was opened to the public in 2014 and Oxalis Adventures offers a five day tour for a mere $3,000 per person.
Above the ground, most of the mountainous park is covered with dense tropical evergreen jungle, more than 92% of which is primary forest. The 1,200 square kilometer national park was declared a Unesco World Heritage Site in 2003 but was only recently opened to the public in 2010. Today access is still very limited and strictly controlled by the Vietnamese military mainly because the park is still riddled with unexploded ordnance, remnants of the Vietnam War.
We came to the park eager to explore the caves and signed up for a tour that included Thiên Đường Cave and Hang Toi Cave. Our trip started out on a loop that included Highway 20 and the Ho Chi Minh Trail West, roads that were built during the Vietnam War to move troops and materials form North Vietnamese Army (NVA) to the National Liberation Front (Viet Cong) in the south. Along these two roads, scars from American bombs that were dropped to interrupt these supply lines are still visible on the sides of the mountains.
Thiên Đường Cave, more commonly known as Paradise Cave, was discovered by a local man in 2005 and was later surveyed by the British Cave Research Association that year. The cave is 31 kilometers long, with chambers reaching to over 100 meters in height and 150 meters in width. Visitors are restricted to the first kilometer of the cave, however, some tour groups offer further exploration of the following six kilometers.
A long descent down a grand, wooden staircase leads to a long wooden walkway and various viewing platforms. Hoping to explore in relative peace in quiet, we were at first shocked (and slightly horrified) by the amount of tourists descending the stairs. When we reached the bottom of the stairs, however, the cave became so massive that people spread out and we were no longer stuck in a bottleneck of selfie-taking domestic tourists. At times we were lucky enough to have small stretches of the cave to ourselves. The one kilometer walkway extended past colossal stalagmites and stalactites that took unique forms that we had never seen before.
After Paradise Cave we headed to Hang Toi Cave, also known as Dark Cave. We entered the cave by zip lining 300 meters across and down the river to the entrance. To get to the entrance, we waded in waist deep, icy water that took our breath away, but was incredibly refreshing in the sweltering afternoon heat.
In the cave, we donned our hard hats and head lamps and headed into the darkness. The entrance of the cave is 30 meters high and 10 meters across, however, the walls got tighter and tighter the further in we trekked. Soon we were inching and sliding our way through narrow mud covered gullies. Then we reached the mud pools and we became head to toe covered in mud. The sensation of floating in the cave mud was truly unique. It seemed impossible to sink. The mud is supposedly great for your skin as well, and some people began scrubbing themselves with it. I refrained and tried not to think of the other hundreds of people who had also ‘bathed’ in this trapped mud pool over the years 🙂
After a rinse in the river and a swim back to the entrance, we hopped in kayaks and paddled our way back to our starting point. Awaiting us there was a smaller zip line and a cooler full of beer. All in all an excellent trip!
The best way to explore Phong Nha-Kẻ Bàng National Park is by renting a motor bike and driving the limited roads that traverse the park. We spent the day cruising along the roads that took up and over limestone peaks and along crystal clear blue-green rivers. The water was so inviting (and it was so hot!) that we pulled off the side of the road and took a dip in the river.
We ventured on our motor bike three kilometers outside of town on a bumpy dirt road to The Pub With Cold Beer. The Pub With Cold Beer is a family-run establishment that serves just what it advertises, cold beer and also chicken. We had heard rumors that you actually pick out your chicken and have the option to kill it yourself. We fortunately didn’t make it that far, however.
Once we arrived, we came upon an unexpected scene. As we parked the bike, we noticed we were surrounded by locals and we were quickly asked if we wanted to join them in a celebration of remembrance of the hosts grandparents. We were nervous at first, but were so enthusiastically welcomed that it was hard to say no.
We were told to sit with this group of young men around a generous helping of food. What commenced next, we were truly not expecting. We were handed glasses filled with beer and a series of cheers commenced and everyone chugged their drink. Glasses empty, they were filled again, and everyone cheers and drank. This repetition continued for the next couple of hours only to be briefly stopped when they passed around food. Needless to say, we had a lot of fun and plenty of laughs with these guys.
After an amazing time in Phong Nha-Kẻ Bàng National Park, we headed further north towards our final destinations in Vietnam, Hanoi and Ha Long Bay.