The Longyou Caves are among the most mysterious ancient sites in domain history . Built around 2,000 years ago , these homo - crafted cavern rest in obscurity for century until they were accidentally key out by Fannie Merritt Farmer in the 1990s .

The sandstone cave are place near the village of Shiyan Beicun on the Qu River in Zhejiang state , easterly China . The caves were found in 1992 when local Farmer drained several ponds revealing five great cavern . later on work then reveal a further 19 small caves at the site .

As a2009 studynotes , the 24 cave come up in varying sizes , ranging from 18 to 34 meters ( 59 to 111 feet ) in width and 8 to 18 meters ( 26 to 59 feet ) in tiptop , concluded with lofty aslant roof and amazingly solid pillars .

In the old age keep abreast its uncovering , archaeologists fromChina , Japan , Poland , Singapore , and the US flock to the setting . The cave were found to hold historical keepsake from the reign of Emperor Xuan of Han who live from 91 to 48 BCE , suggesting the cave was spirt by man over 2,000 years ago .

The age was gobsmacking . Experts struggled to explicate how the cave managed to maintain their integrity for more than 2,000 long time . Furthermore , any armchair archaeologists can point out that these sure do n’t seem like many complex body part created 2,000 class ago .

depend at the stripes in the cave wall , we can guess that they were somehow build by chiseling away at the earth level by stratum , but there ’s little idea of how the caves were constructed . Indeed , no ancient record of the caves or their expression have ever been recover .

Perhaps the only structure similar to the Longyou Caves are theHuashan Grottoes , but these are found 200 kilometers ( 120 sea mile ) by in another pocket of China and were likely built 1,500 yr later .

It ’s also a mystery why ancient people went to such great lengths to make these caverns . Was this a protection , a military bunker , a ceremonial body structure , a secret castle of the elite , or a mine for rude resources ?

One hypothesis put forward in 2014 by Yang Hongxun , a research worker at the Institute of Archaeology of the Chinese Academy of Social Sciences , is that the caves were build up under the statement of the ancient king Goujian in 494 BC . According toChinese media , Hongxun argues that Goujian used the caves to veil his G of soldiers conform to a squeeze defeat in battle .

Truth be told , many facial expression of the Longyou Caves remain a secret , although one matter is fairly certain : it wasn’taliens .