The Longyou Caves: One of China’s Greatest Mysteries

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The Longyou Caves are located near the village of Shiyan Beicun in Zhejiang province, China. They are a vast, magnificent, rare ancient underground world regarded as “the ninth marvel of the ancient world” in China.

Also known as the Xiaonanhai Stone Chambers, thes caves are at least 2,000 years old. Today, they are one of the enduring enigmas that have baffled specialists from every field. So what is it about these caves that is so puzzling?

In this article, we will examine the Longyou Caves and some of the things that these experts are struggling to understand. Being some of the largest ancient underground excavations, it’s only right that we take a closer look.

The striations on the ceiling and walls of the Longyou Caves is shown.

Origins of the Longyou Caves

The archaeologists, architects, engineers, and geologists of the world have yet to learn how, by whom, or for what purpose the Longyou Caves were constructed. In 1992, a local villager named Wu Anai grew dissatisfied with the legend that the ponds lacked a foundation.

He convinced some of his neighbours to assist him in renting an industrial pump. They drained every drop of water from the adjacent “bottomless pond.” They observed no fish or other life forms, unlike other “bottomless ponds” they were familiar with.

When the water ceased to trickle from the pump, they entered the rock crevice. They were surprised by what they discovered.

They discovered a 98-foot-deep (equivalent to the height of a 10-story building), roughly 11,000-square-foot cavern carved out of the local sandstone.

Massive pillars supported the roof, and the pillars, walls, and roof were all carved out using a distinctive arrangement of parallel bands or courses that were each about 24 inches (a cubit and a span) wide. The chisel marks on the bands were consistently situated at a 60-degree angle to the course’s axis.

From the surface to the depths of the grotto, intricately crafted stairs and passageways descended. The walls and pillars were adorned with intricate engravings and symbols (none of which have been translated or interpreted). The total area covered by the grotto is greater than 3,500 square meters.

Longyou Caves Archaeology

Observing the excavation marks on the interior cave walls shows these caves are artificial. Some believe these engravings are symbolic because these drilling marks have produced parallel grooves on all the walls.

These signs are identical to the engravings found on a container that dates back to 500 to 800 B.C. and was discovered near the city’s museum many years ago. These caverns have stairs and columns, and an icon is etched into the walls.

Some of the wall art found in the Longyou Caves is depicted.

24 separate chambers

Government officials and academic experts were consulted. So far, 24 cavities have been found in nearby areas that have been surveyed (one of them has been developed as a tourist attraction). To date, 24 hand-carved caves encompassing a massive 30,000 square meters have been discovered (322,917 ft sq).

Each cave is approximately 30 meters (98 feet) underground and consists of stone chambers, bridges, gutters, and pools carved into solid siltstone.

Within the Longyou Caves, the ceiling is supported by equitably distributed pillars, and the walls, ceiling, and stone pillars are uniformly decorated with chisel marks in a series of parallel lines.

One of the caverns has been opened to tourists because it contains stone carvings depicting a horse, a fish, and a bird.

The Longyou Caves in China’s Zhejiang province is interesting to say the least. Let’s see some of the mysteries that remain unsolved after more than two decades of research.

The Mysterious Longyou Cave System

The Longyou Caves contain numerous mysteries, some of which remain unresolved. These mysteries are clarified in greater detail below.

How Did the Longyou Caves Come to Be?

An approximate estimate of the labour required to construct the Longyou Caves is astounding. It is believed that approximately one million cubic meters of limestone would have been removed during the excavation of the caves (35,314,666 cu ft).

Scientists have predicted that it would take 1,000 individuals labouring day and night for six years to complete, taking into consideration the average pace of digging per day per person.

The above calculations are based solely on manual labour, but they do not account for the extraordinary care and precision of the sculptors so the actual workload would be significantly greater than the theoretical estimate.

How they were constructed, and with what instruments still need to be discovered. No tools have been discovered in the region, and, as we will see in a moment, scientists still need to learn how the caves’ symmetry, precision, and similarity were accomplished.

Some tourists walk down the stairway into one of the main chambers in the Longyou Caves.

No Evidence of Construction

Despite their immensity and the effort required to create them, archival sources have yet to reveal any evidence of their construction or existence.

Although the overall excavation involved nearly a million cubic meters of stone, archaeological evidence indicates where this quantity of stone went, and there is evidence of the operation.

In addition, only a few historical documents mention them, which is extremely unusual given the project’s scope. The origin of the Longyou Caves is a complete enigma.

Why Were the Walls Carved Out?

Parallel lines have been incised into virtually every surface of the Longyou Caves, from floor to ceiling. The effect is a uniform pattern throughout the caves, which would have required enormous labor and countless hours to produce.

But what purpose did they serve? Was such labor-intensive work solely for aesthetic purposes? Are the lines or motifs somehow symbolic? All that is presently known about the markings is that they resemble those discovered on pottery in a nearby museum between 500 and 800 BC.

Some claim that these caverns were excavated more than two thousand years ago, around 200 B.C., and that approximately one million cubic meters of rock were removed to create them.

Historians and tourists must have documented a project of this magnitude, yet nowhere is it mentioned that it was constructed. This surprised archaeologists, as the ancient Chinese meticulously chronicled all historical events.

How Have the Longyou Caves Been Preserved So Well?

How the Longyou Caves have maintained their structural integrity for over two thousand years is one of the most intriguing and difficult questions. Even though some of the walls are only 50 centimetres (20 inches) thick, there are no indications of collapse, piles of rubble, or damage.

The area has endured numerous floods, disasters, and conflicts over the centuries, the mountains have changed appearance, and exposed stones have been weathered, but inside the Longyou Caves, the form, patterns, and markings are as clear and precise as if they were constructed yesterday.

Who Constructed the Longyou Caves?

Who constructed the cavern? Some scientists have asserted that it was not possible or logical for villagers to have performed such a monumental task.

A massive undertaking like the building of the Great Wall, which was done to stave off an attack from the outside world, could only have been managed by the emperor and other leaders. Why are no historical records of its construction if an Emperor commissioned it?

A couple of the large pillars in the Longyou Caves are shown, surrounded by artificial barriers and lighting for tours.

How Did they Attain Such Precision?

The Longyou Caves’ dimensions are grand and historical, their delicate and scientific design was executed with skill, and their precision reflects high levels of craftsmanship. Each cave’s design, pattern, and aesthetic are remarkably similar.

Each grotto resembles a stately hall. One side is steep, and the opposite is 45 per cent inclined. The four walls are parallel, and the edges and extremities are distinct. Within the Longyou Caves, the chiselling traces are uniform and precise.

“According to Yang Hongxun, an expert at the renowned Archaeological Institute of the Chinese Academy of Social Sciences, “at the foot of each cave, the ancient builders could not see what the others were doing in the next grotto.”

However, “the interior of each cave had to be parallel to the interior of the other, or else the wall would be pierced.” Consequently, the measuring equipment should have been highly sophisticated. Prior planning must have determined the caverns’ sizes, locations, and distances from one another.”

Using modern apparatus and techniques, the investigators measured the dimensions of the walls and discovered, to their surprise, that the overall construction was extremely accurate.

The walls between the caverns are of uniform thickness at various points. How did they accomplish such accuracy? What strategies did they use?

How Did the Builders Operate in the Dark?

Due to the vast depths of the caves, some areas at the bottom are completely dark. Explorers discovered that even these shadowy areas flaunted thousands of parallel lines on the ceiling, walls, and columns. So how did ancient humans accomplish these tasks in the dark? Or was another force at work?

As per Jia Gang, an expert in civil engineering at Tongji University, “There should be lamps because the cave’s entrance is very narrow and the sunlight could only enter the cave at a specific angle and time.

As one progresses deeper into the cave, the light dims. Visibility is typically poor at the bottom of the cave, typically dozens of meters from the entrance.” However, since this occurred at least 2,000 years ago, evidence of illumination has yet to be discovered.

Were the Longyou Caves intended to be linked?

The entire territory the Longyou Caves occupies is only one square kilometre (0.38 sq mi). Given this density, one cannot help but wonder if some grottoes were intended to be connected.

Why would it be necessary to create so many distinct caverns in such a little space without connecting them? In many regions, the walls between caverns are only 50 centimetres (20 inches) thick, but they were never connected, so it appears they were deliberately kept apart. In addition, many of the Longyou Caves are virtually identical.

Absence of Fish in the Longyou Caves

When the caverns were first discovered, they were presumably filled with water that had been there for a very long time. The water had to be drained out for them to realize that these were not the same as the other “bottomless ponds” in the area but rather structures created by humans.

Most villages in southern China contain extremely deep ponds, which generations of villagers call “bottomless ponds.” These wetlands are teeming with fish that are easy to catch. However, after the first cave was pumped empty, no fish or other signs of life were found.

A large chamber is shown, with natural light coming in through a massive opening above it.

The Theories that Remain Today

Scientists and scholars have attempted to explain some of these mysteries, but have yet to do so convincingly despite extensive research.

An Emperor’s Tomb

Some archaeologists believe the caves were the tombs of ancient emperors, emperor chambers, or storage facilities.

However, this interpretation is implausible. No grave goods or tombs were discovered, nor were any antiquities left behind. If the caves had been used as an emperor’s palace, they would have been designed differently, with distinct rooms for entertaining, meeting, and sleeping. But there is no evidence of this, and no traces of habitation have been discovered.


A second possibility is that the Longyou Caves were utilized for mining and mineral extraction. Mining operations require equipment and apparatus to extract and convey the rocks.

Again, no traces of this or evidence of where the rocks were removed have been discovered. Why decorate the walls, columns, and ceilings with such intricate designs, if mining was the only goal?

Shelter for Troops

Lastly, some have hypothesized that these caverns once housed troops and that an ancient emperor wished to conceal his war preparations by hiding his soldiers.

However, it’s likely that construction happened slowly. They would have taken many years to construct, so it is improbable that they were constructed in preparation for war. War typically demands much more rapid action than something like this. In addition, there are no traces of human habitation in the caverns.

Despite decades of investigation, the mystery of the Longyou Caves remains largely unexplained. Our ancient ancestors have accomplished many wondrous feats, but this discovery from China remains an unsolved enigma.

What do you think? Let us know!

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