Thien Cung Cave

Inside a hill on Đầu Gỗ Island, in the southwest of Ha Long Bay, there is a vast empty space. It began about 2 million years ago, when groundwater started to dissolve the limestone from within. The water drained away, and the hollow stayed behind. Then drops seeping through the rock, carrying minerals with them, began to draw columns, clusters and thin sheets of stone into that space. They kept at it for millions of years.

The cave is called Thiên Cung, which means a palace in the sky. Whoever first named it must have seen something that brought a palace from legend to mind.

It lies about 4 kilometers from Tuần Châu port, on the slope of the island. The mouth of the cave is about 25 meters above sea level, and the way up is a stone stairway through thick tropical growth. The cave covers almost 10,000 square meters in three chambers, and it is one of the largest and most beautiful caves in the bay.

The Ha Long Bay Management Board classes Thiên Cung as an ancient underground cave. That is a cave formed when the underground water level dropped and left the hollow system inside the limestone exposed.

The first chamber is the first one visitors enter. On its north wall, the lamps pick out a mass of stalactites whose shapes bring figures from legend to mind. A local folk story, recorded by the Management Board, says this is where the Dragon King's crown prince held his wedding. The feast lasted seven days and seven nights, and dragons, elephants, lions and celestial beings came to it. The story is a layer of imagination laid down by people long ago, not a historical event. What is truly here are the wonderful stone forms that nature made over millions of years.

The second chamber is the center of the whole cave, and the most striking part. Four huge stone columns stand in the space. Each formed where a stalactite from the ceiling met a stalagmite from the floor, after drip upon patient drip. The Management Board calls them the four pillars. They may have taken anywhere from hundreds of thousands of years to millions of years to form. Above them the ceiling arches high, and the stalactites hang thick as curtains. Lamplight reflects off them in a way unlike anything most visitors have seen.

The third chamber is smaller and stiller. It holds a pool of very clear water, fed all year by water flowing naturally down from above. Light bouncing off the water and the stalactites makes an effect that is hard to describe in words.

Yet Thiên Cung keeps one more thing that few people notice. The cave is an archaeological site of the Soi Nhụ culture, a prehistoric culture dated from 7,000 to 18,000 years before the Common Era. Archaeologists found a layer of Melania snail shells here, turned to carbonate, and stone tools in the cave. The evidence shows that prehistoric people lived here, or at least were active here, many thousands of years before anyone gave the cave its name.

On the cave wall there is also a line of writing with the year 1901. Who left it is not known. But it is a sign that people knew of the cave from the early twentieth century. Fishermen then found it again in 1993, and it officially opened to visitors on May 1, 1998.

So this cave carries a long record: 2 million years of geology, prehistoric people up to 18,000 years back, an unexplained line of writing from 1901, a rediscovery by fishermen in 1993, and an opening to visitors in 1998.

Standing among the four pillars, looking up at the vaulted ceiling hung with stalactites like curtains, and listening to water drip somewhere in the dark, one can understand why people long ago called this a palace in the sky.