The underground Great Wall is a ancient war tunnel built in AD 960 to 1127 in order to guard against Liao Dynasty’s aggression; so far the discovered part of the whole tunnel is 65 kilometers long from east to west, 25 kilometers wide from south to north, covering an area of about 1300 square kilometers.
Within it there are also several sitting rooms with air vents, water vat and other living facilities, as well as some military facilities like various traps, bunkers, double walls and so on. Additionally connected to outside wells, temples, stone towers and shops and other buildings...
As a national secret military project, it was't recorded in history, so wasn't discovered until 1950. Later it's named the Underground Great Wall located in Yong Qing County, China.
The pictures are from here.
Within it there are also several sitting rooms with air vents, water vat and other living facilities, as well as some military facilities like various traps, bunkers, double walls and so on. Additionally connected to outside wells, temples, stone towers and shops and other buildings...
As a national secret military project, it was't recorded in history, so wasn't discovered until 1950. Later it's named the Underground Great Wall located in Yong Qing County, China.
The pictures are from here.
