As the capital of the Yuan Dynasty, Ming Dynasty, Qing Dynasty, and the People's Republic of China, there are many myths and legends about Beijing. The most well-known is that Beijing, like many other ancient capitals, has a "dragon vein", 龙脉, an important feng shui phenomenon that can affect the fate of a nation. According to a more local legend, Beijing doesn't just run on "dragon blood", there is a whole dragon imprisoned underneath the capital city's ground. The door to its prison is located in downtown Beijing, near the lantern-stringed restaurant street Gui Jie (簋街) and the Line 5 subway station Beixinqiao (北新桥).
The prison door is, in fact, a well, and the dragon imprisoned down below by large chains. If you wonder how it'd be possible for a dragon to fit into a well, aside from there being a dragon in the first place, the "eye of the ocean" solves the size issue. The well is in fact an "eye of the ocean" (海眼), a term that refers to a seemingly endless water hole in the ground that reaches deep into the earth , believed to reach into the depth of the sea and the eye of the ocean on land.
According to the legend, the dragon has been chained underground since the founding of Ming dynasty when the city of Beijing was built. Liu Ji, a legendary figure with insurmountable knowledge in the mystics , poetry, and strategizing among others, is rumored to be the person who identified the "eye of the ocean" as well as the dragon. The ancient dragon (in some versions a dragon family) had occupied the land of Beijing long before they arrived to set up capital, and was infuriated at the intrusion of his home. He vowed to use his powers to flood the whole city (contrary to Western fire-breathing dragons, Chinese dragons command water and rainfall). Anticipating the dragon's revenge, Liu Ji asked another legendary figure Yao Guangxiao to defend the city they built while he was gone.
　　
