The ten unsolved mysteries of Longyou Artificial Caves, China
The Longyou Caves are a system of large artificial caves located near the village of Shiyan Beicun, in Quzhou Prefecture, China. Discovered in 1992, 36 caves have been identified so far. Considering their artificial origin, these are very large caves, with a covered surface exceeding 30 km². Who built them and above all why? Here are the ten unsolved mysteries of Longyou Caves.
Located near the village of Shiyan Beicun in Zhejiang province, the Longyou Caves are a magnificent and rare underground world, considered in China as the 'ninth wonder of the world'.
These fascinating artificial caves, which are thought to date back at least 2,000 years, represent one of the greatest underground architectural works of ancient times.
Scientists and archaeologists from all over the world, however, have not yet managed to reveal its secrets, leaving unanswered the questions of who built them and above all why.
The cave system was discovered in 1992 by a local villager. Since then, around 36 artificial cavities have been explored, for a total surface area of more than 30 thousand m2. The caves were dug into solid siltstone and each of them sinks to a depth of approximately 30 m.
The landscape is dotted with bridges, gutters, pools and pillars uniformly distributed throughout the structure with the aim of supporting the vaults of the caves. The walls and supporting columns were excavated with great precision, covered with decorative parallel lines made with a chisel.
Of the 36 caves, only one is currently open to the public, chosen because inside there are stone sculptures depicting horses, fish and birds.
The Longyou Caves are a real enigma for scholars. Here I propose ten still unsolved mysteries about them.
1. How were the Longyou caves built?
A rough estimate is that to create the caves a quantity of rock equal to 1 million m3 was removed. Taking into account a person's average daily digging rate, the scientists calculated that it would take at least a thousand people digging day and night, non-stop, for six years.
However, the calculation does not take into account the incredible care and precision with which the cavities were made. This means that the workload could far exceed the theoretical estimate. Furthermore, the tools used for the excavation are completely unknown. In fact, none of them were found inside the caves. Scientists do not know how such symmetry, precision and similarity between the various caves could have been achieved.
2. No traces of construction
Despite their size and the effort that went into their creation, so far no trace of their construction, or even of their existence, is reported in historical documents, which is very unusual given the vastness of the project. Furthermore, although the excavation required the removal of one million cubic meters of rock, there is no archaeological evidence to explain where the resulting material ended up.
3. Why were the walls engraved?
The Longyou Caves are all chiseled, from floor to ceiling, with parallel lines on virtually every surface. The final effect is one of great uniformity, which required immense expertise and endless hours of work.
The question is: why? If the purpose was only decorative, why invest so many hours of work? Do they have a symbolic value? The only known similar decoration is found on some ceramics housed in a nearby museum and which are dated between 500 and 800 BC
4. Lack of aquatic life forms
When they were discovered, the cavities were submerged in water, presumably for some time. Initially, in fact, they were thought to be 'bottomless ponds'. Only when the water was completely pumped out was realized that were artificial structures.
Most villages in southern China are located near very deep (so-called 'bottomless') natural ponds. These water reserves are teeming with a wide variety of fish. However, when the water was removed from the Longyou Caves, not a single fish or any other life form was found.
5. How did the Longyou caves remain so well preserved?
One of the most interesting questions is understanding how the caves have managed to maintain their structural integrity for more than 2 thousand years. There are no signs of collapse, no piles of rubble, despite the fact that in some areas the walls are just 50 centimeters thick.
Over the centuries, the area has suffered numerous floods, disasters and wars. Due to geological movements, the mountains have changed their morphology, but the interior of the caves, the shape and the engravings have retained their original precision, as if they had been built yesterday.
6. How did the builders work in the dark?
Due to the great depths of the caves, some areas in the lower part are immersed in total darkness. Yet even the walls of these areas were decorated with thousands of parallel lines. How did they work in the dark?
According to Jia Gang, a professor at Tongji University specializing in civil engineering, the builders would have used fuel lamps. However, given the immensity of the rooms, hundreds of lamps would have had to be used. The curious fact is that the ceiling of the caves shows no signs of soot.
7. Were the caves designed to be connected?
Despite the total surface area of 30 thousand m2, the 36 caves are distributed over a very small area. Considering such a density, it is questionable whether the caves were designed to be connected to each other. What would be the purpose of creating many separate caves, at close distances, without connecting them?
In many areas, the walls that separate the caves are very thin, only 50 cm, but they are never connected, so as to appear as if deliberately separated from each other.
8. Who built them?
It is believed that the caves date back to an era before the birth of the Qin dynasty, which arose in 212 BC. However, no one has any idea who could have achieved such a feat. Some researchers argue that it is neither possible nor logical that the titanic undertaking was undertaken by the regular inhabitants of the nearby villages.
Only an emperor could have commissioned such a feat, such as the construction of the Great Wall. But if it was commissioned by an emperor, why are there no historical documents attesting its existence?
9. How did they achieve such precision?
The design of the Longyou Caves is delicate and sophisticated, and the precision of the construction is indicative of the highest level of craftsmanship. Each cave is like a large hall. The four walls are straight and the edges and corners clearly delineated. The chiseling marks are uniform and precise.
As Yang Hongxun, an expert at the Archaeological Institute of the Chinese Academy of Social Sciences, explains, ancient builders working in one cave were unable to see what others were doing in the nearby cave. Yet, the walls of the adjacent caves had to be parallel, otherwise they would have broken through the wall sideways.
This means that the measurement techniques had to be very advanced. The builders were in possession of a sophisticated system for mapping the caves, capable of calculating the dimensions, position and distances between the caves in advance. With the help of modern equipment, the researchers were able to confirm the surprising precision of the construction as a whole.
10. What were the Longyou Caves made for?
Many theories have been put forward to try to explain why the caves were built, but so far none of the proposed hypotheses can provide a convincing explanation for their use.
Some archaeologists have suggested that perhaps the caves were the tombs of ancient emperors. But it is an unlikely hypothesis, given that no funerary objects or tombs have ever been found inside them.
Others have proposed that it is the result of mining. The operations would have required equipment of a certain type.
Also in this case, no such trace was found in the cavities to support the hypothesis. And then, if they were just mines, why create such precise decorations on every surface of the cavity?
In short, despite decades of research, the Longyou Caves still represent an unsolved enigma. What is certain is that we are understandin more and more that our ancestors were capable of creating wonderful works, but the Longtou cavities are truly an inexplicable mystery.
