by A. Sutherland

January 16, 2019

from AncientPages Website

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Fascinating and mysterious underground Longyou Grottoes (also known as Longyou Caves) must have been some kind of an extraordinary man-made project of the ancient skilled builders, who created them more than 2000 years ago.

They have long been the subject of great fascination for both scholars and laymen alike but until now, no one was able to solve the mystery of their creation.

Researchers from several countries around the world visited and investigated the Longyou Grottoes, which are believed to date to a period before the creation of the Qin Dynasty in 212 BCE.




Description Of The Caves

The caves are very large considering their man-made origin:

the average floor area of each cave is over a 1,000 square meters(11,000 sq ft), with heights of up to 30 meters (98 ft), and the total area covered is in excess of 30,000 square meters (320,000 sq ft).


The ceiling, wall and pillar surfaces are all finished in the same manner, as a series of parallel bands or courses about 60 cm wide containing parallel chiseling marks set at an angle of about 60° to the axis of the course.


They have maintained their structural integrity and appear not to interconnect with each other.

The areas of grottoes differ from 1,000 to 3,000 square meters. Each grotto makes a downward vertical extension from the rectangular hole with a height of approximately 30 meters.

The Longyou Grottoes are located at Phoenix Hill, 3 km north from Longyou County Quzhou prefecture, Zhejiang province, China.




Anonymous Builders, Unknown Purpose Of Construction

Unfortunately, there are no historical records of their construction, no construction plans or methods of their design have ever been found.


  • Why have these large artificial sandstone structures been able to maintain the stability for so long?


  • Were they constructed by ancient Chinese or an unknown very advanced civilization present in the region at that time?




Decorated With Lines And Symbols

The walls, roof, and stone columns of each of the grottoes are decorated with chisel marks - lines and symbols - probably deliberately left by the ancients.

Do these symbols have only ornamental purpose, or are there a hidden message within the walls that has yet to be deciphered?

Among twenty four discovered grottoes - all of which were carved by hand - there are seven that are decorated with patterns clearly resembling the seven stars of the Big Dipper.


None of the caves are connected with each other, but many of them share thin walls.


As Yang Hongxun, an expert at the Archaeological Institute of Chinese Academy of Social Sciences, explained,

"at the bottom of each cave, the ancient builders wouldn't be able to see what the others were doing in the next grotto.


But the inside of each cave had to be parallel with that of the other, or else the wall would be holed through. Thus the measure apparatus should have been very advanced.


There must have been some layout about the sizes, locations, and the distances between the caves beforehand."

Many questions regarding the Longyou masterwork have never been answered.

  • Where was the excavated rock from the grottoes transported?

  • How many workers were involved in creation of these extremely sophisticated grottoes?




The four caves, for example, cover an average floor surface of 1,200 square meters, so each of the caves should have involved excavation of 36,000 cubic meters of stone.


Since a total of 24 such caves have already been found in Shiyanbei Village, the overall excavation would be 900,000 cubic meters.




Could Ancient Chinese Build Them?

According to an estimation:

if one man can dig and carry out 0.5 cubic meter of stone every day, then building these 24 caves would require 1,000 strong men to work 24 hours a day, seven days a week for about 5 years.

However, this is only a conservative estimation, because,

'the deeper the cave goes, the more difficult in excavation and transportation will be.'

One theory suggests that large rock grottoes fully filled with water can be stable and integrate for thousand years. Other issues must wait for answers.

The modern rock mechanics and rock engineering are younger than 100 years and have never contributed with this kind of very advanced constructions.