Everybody knows the Great Wall of China, but maybe you don’t know “Underground Great Wall” of China.

There is an ancient tunnel that area is about 300 square kilometers in Yongqing County of Hebei Province, China. This tunnel was built in Sung Dynasty. It has already had a history of more than 1000 years. Sung Dynasty was at war with Liao Country of north of China at that time. Here is frontier of Sung Dynasty, and here is plain. Therefore, Sung Dynasty built the tunnel fortifications here.

This tunnel has already been hidden underground for more than 1000 years. A peasant discovered this tunnel in 1951. The experts call it “Underground Great Wall”.

This ancient tunnel is not only large-scale, but also the structure is complicated, and the layout is strictness. It connects 11 villages. There are military installations such as blindage, gate, barracks, etc. in the tunnel; there are also life facilities such as air vents, lampstand, adobe kang (heatable brick bed), etc. The building material of the tunnel is huge blue brick of 30*16*8 centimeter.

Therefore, this is a large-scale permanent underground military project which the government of Sung Dynasty built. As we know the Great Wall is a great military defense project in ancient China, but this ancient tunnel’s actual function compared favorably with the Great Wall at that time. Its historical significance and value are immeasurable. However, only few of people know it so far, so I introduce it to everybody. If you want to travel to China, maybe this is a very good place.