The Longyou Caves in Zhejiang, China are one of the little-known wonders of the world.
This complex of ancient man-made caves was discovered over thirty years ago. It has since become a popular tourist attraction, but the original purpose of these massive caverns remains a mystery.
Discovering the Longyou Caves
For centuries, villagers living near the Longyou Caves fished and washed their clothes in nearby ponds without even knowing what was hidden beneath.
In 1992, a group of locals led by Wu Anai decided to investigate this local phenomena. They set up a pump to remove water from one of these “bottomless ponds”. After over two weeks of pumping, the water level went down enough for them to realize that the town’s beloved bottomless ponds weren’t bottomless after all – they were the long-forgotten entrances to massive man-made caves.
Five enormous caverns were discovered, along with nineteen smaller caves. Each cavern had only one opening to the world above, and none of the rooms were connected to each other.
Glazed clay pots excavated from the cavern floor were dated to the Western Han Dynasty, which lasted for over two centuries – from 206 BC to AD 23. This tells us that the caves are at least two thousand years old.
These man-made caverns go one hundred feet underground. Intricately carved pillars support the ceiling, and the walls are carved with parallel lines running in a uniform pattern from top to bottom. Sophisticated drainage systems channel water into deep pools.
Deep within the caves, sunken rectangular pools still hold water. Each pool is about fifteen feet deep and filled by natural springs or an underground river. To prevent flooding and maintain access to the caves, water is pumped out to keep them from filling up again.
Each room has four straight walls and 90-degree corners. Each ceiling slopes down from the entrance at a 45-degree angle. In addition to the parallel lines created by carving tools, there are intricate three-dimensional carvings on many of the walls and columns.
Over thirty years after they were discovered, the origins of these caves are still shrouded in mystery.
Some scholars insist that ordinary country folk could never have accomplished such a feat of engineering, and this project must have been organized by the upper class, possibly even the emperor. But to this day, no historical records documenting the construction of the Longyou caves have been found.
The calculations required to complete this work are astounding. Though the caves weren’t connected (locals have since cut through some walls to make things easier for tourists), the rooms run parallel to each other. In some places, the walls are less than two feet thick.
The purpose of the caves is also a mystery. Some scholars have suggested that they were created to house and hide military troops, but the time that would have been required to create these caves suggests otherwise. Others have suggested storage or tombs, but no artifacts were found within to support that theory.
The work that went into creating these caverns is astounding. Workers removed around one million cubic meters of rock. Even if there were one thousand people working round the clock, the project would have taken around six years to complete.
Even the how of these caves continues to baffle archaeologists, who found little evidence of construction work. Archaeologists found short steel chisels in one of the larger caverns, but the extent of the construction and the final location of the massive amount of stone moved still remains a mystery.
What’s more, there’s no evidence of fires or oil lamps that would have provided the light required to complete this intricate work. Southern-facing entrances provide some sunlight, but they only illuminate small sections of the cave.
The staying power of the caves is yet another mystery. They’ve stood for over two thousand years, through earthquakes and floods. Though they were covered by water for centuries, the intricate carvings within the caves are still clearly visible.
During this period of time there were mine shafts being created at similar depths elsewhere in the lands controlled by the Han dynasty, but these caverns are far too immense and detailed to be simple mines.
While the purpose of the caves has been lost to history, the means by which they were constructed isn’t quite so mysterious as many sources like to pretend. The civilization that birthed them was advanced.
The Western Han Dynasty
Archaeologists believe that these caves were constructed during the Western Han dynasty, which was an imperial dynasty that began in the year 202 BC and endured for over two centuries. The economy of the region prospered during that time, and large construction projects were not uncommon.
The intricate carvings found in the Longyou caves are typical of the Han Dynasty, which saw the creation of a great deal of art. Murals and relief sculptures were common, as were detailed ceramic sculptures. Intricately carved stone pillars were common in ancient China.
We can guess that derricks were used to move the stone, because that technology was used in mines in that region around the time that these caverns were constructed.
There are other examples of advanced mechanical engineering being used in the region at that time, such as waterwheels, belt drives, and precise measuring instruments. Sophisticated drainage systems have been unearthed in various locations, such as Chang’an and Luoyang.
The five largest caverns are now open to visitors. Longyou is about two hours away from Shanghai by train, and it’s become a popular tourist destination. From the station in Longyou, it’s only about a ten-minute taxi ride to the caves.
Some of the caverns have intricate carvings of men and beasts. Stone dragons wind their way up the enormous pillars that support the cavern ceilings. Some of the dragons appear to be diving into the ground, their heads out of sight, which begs the question of how much further down the stone carvings might go.
Some carvings depict lines of travelers in flowing robes, some of them mounted. Other carved figures carry logs while others sweep. There are trees and flowers, towers and homes with long trails of steps leading up to the doors.
There are still ponds yet to be drained and more caverns to discover.