Thousands of years ago, the mysterious builders of the Longyou caves had the technology and means to remove and transport nearly 1,000,000 cubic meters of rock.
Furthermore, what makes the Longyou Caves even more fascinating is the fact that there are NO historical records that mention the mysterious underground complex.
First discovered in 1992, 24 caves have been found to date, one of which has been developed as a tourist attraction.
The caves were carved in sandstone, a homogeneous medium-hard rock, and are thought to date to a period before the creation of the Qin Dynasty in 212 BCE.
The caves are notable in several respects:
The caves are very large considering their man-made origin: the average floor area of each cave is over a thousand square meters, with heights of up to 30 meters, and the total area covered is in excess of 30,000 square meters.
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.