Paradise Cave

At the foot of a limestone mountain in Phong Nha, 524 stone steps climb toward a cave mouth. A sloping path, 570 meters long, makes the same climb. Up there waits one of the most beautiful dry caves in Asia.

Inside the cave, the temperature holds steady at about 20 degrees Celsius all year round. The air is cold and clear, a sharp contrast to the heat outside.

The story of this cave began in 2005. A local villager named Hồ Khanh was walking in the forest when he felt a cool breeze coming out of a crack in the rock. He kept the place in his memory, and then he reported it to scientists.

A team from the British Cave Research Association went in to survey it, led by Howard Limbert. They worked together with Vietnamese scientists, and they measured the cave from that year until 2010. The result was a cave 31.4 kilometers long. It is between 30 and 100 meters wide, and in places as wide as 150 meters. The ceiling rises as high as 60 meters.

This is a dry cave, which means that no underground river flows regularly along the standard route. That is also why the cave was given the name Thiên Đường, which means Paradise. The survey team had reached a wide vault of white stalactites, and it felt like stepping into another world.

The Trường Thịnh Group invested in the infrastructure, and on September 3, 2010, it officially opened the cave to visitors. And here is a thread that ties two great caves together. The same Hồ Khanh later guided the team that found Sơn Đoòng in 2009. One villager, and two of the greatest caves in the world.

The cave mouth is smaller than what lies behind it. That is the first surprise. The second is the rush of cold air when you cross the threshold.

Ahead stretches a wooden bridge one kilometer long. The Vietnam Book of Records Center has recognized it as the longest wooden bridge inside a cave in Asia. Wood was chosen over concrete for two reasons. It protects the natural clay floor of a dry cave, and it reduces the echo of noise in the open space. The bridge has railings, and the lighting is designed to fall on each stalactite mass from different angles.

Along the bridge, the stalactite masses carry names taken from the shapes they bring to mind. On the right is a formation shaped like a lotus base. Its name is Tháp Liên Hoa. Then come two that rise like the old Cham towers: Cổ Tháp and Tháp Chỉ Thiên. After them comes a wide vault that recalls a house of worship, Đại Thánh Đường.

On the ceiling, a mass of stalactite falls straight from the roof. The lights give it the look of the Milky Way, and it is called Thác Thiên Hà. Farther on are Nhà Rông of the Central Highlands, Thỏ Ngọc, the Jade Rabbit, and Ruộng Bậc Thang, the Terraced Fields.

All of these are tourist names. People of a later time chose them to match natural shapes. They are not geological names that have been there from long ago. Each visitor may see a different shape, and each takes home a picture of their own.

The Terraced Fields deserve a closer look. They are the work of thousands of years. Water dissolved calcium from the ceiling and ran down over the rock, settling in small tiers. Each tier is a step of calcium carbonate. If the water stops flowing, the steps stop growing. Each step holds a vast stretch of time, saved in stone.

A longer route, 7 kilometers, leads deeper. It passes through an area called Hang Dơi, the Bat Cave, and crosses an underground stream before it ends at Giếng Trời. Giếng Trời is a natural karst collapse in the ceiling. Part of the limestone roof weathered away and fell in many thousands of years ago. Now sunlight drops straight down as a single column of light into the dark.

This is a cave that formed about 400 million years ago. It lies inside Phong Nha Kẻ Bàng National Park, a natural World Heritage site listed by UNESCO. A local villager came upon its entrance by chance in 2005. Less than twenty years later, it had become one of the most beautiful dry caves in Asia that people have ever entered.

And every year, from the ceiling 60 meters above, drops of water still fall in silence. Step by step, the calcium carbonate keeps growing, as if the cave were still building itself.