Four bodies of water that metaphorically made up the boundaries of ancient China
The Four Seas (Chinese: 四海; pinyin: Sìhǎi) were four bodies of water that metaphorically made up the boundaries of ancient China. There is a sea for each for the four cardinal directions. The West Sea is Qinghai Lake, the East Sea is the East China Sea, the North Sea is Lake Baikal, and the South Sea is the South China Sea. Two of the seas were symbolic until they were tied to genuine locations during the Han dynasty's wars with the Xiongnu. The lands "within the Four Seas", a literary name for China, are alluded to in Chinese literature and poetry.
