Longyou Caves
The Longyou Caves are found near the village of Shiyan Beicun in the Zhejiang province in China. They are believed to date all the way back to 212 BCE during the Qin dynasty. What makes the caves particularly remarkable is that it would have taken a monumental effort to create them but there is no record at all of their construction or existence. The caves were first found in 1992 and that is the first that anyone had ever heard of the mysterious caves. Since the initial discovery 24 caves have been found and one of them is now a tourist attraction.
The caves are located at Phoenix Hill. They are carved into sandstone and are massive for being completely man-made caves. There average floor space of the caves is 1,000 square meters (11,000 square feet). The height of the caves is also substantial reached up to 30 meters (98 feet) and the total covered area is 30,000 square meters (320,000 square feet).
Throughout the caves are pillars that are evenly spaced in order to support the ceiling. The walls, ceiling and columns are decorated with parallel chisel marks. There are also carvings that depict animals such as a horse, fish and bird. It has been estimated that just to dig out the tunnels would take 1,000 people working around the clock for six years. Added to that the care and precision of the sculpting and the carvings inside the caves would add years to its construction.
The caves are also remarkably preserved. There is no sign of rubble or debris and the carvings are still completely clear and precise. Despite the excellent condition of the caves there remains no evidence of who could have built them. Only someone like an emperor could have commissioned such a massive project but then there is no explanation for why there would be no record of such a project in the historical records. There is also no explanation for why the caves were built or what they were used for.