Guanzhong
From Wikipedia, the free encyclopedia
Guanzhong (關中) (lit. Center of Passes), or Guanzhong Plain, historically refers to an area that was closed by Hangu Pass to the east, Dasan Pass (大散關) to the west, Wu Pass (武關) to the south, and Xiao Pass (蕭關) to the north, including central part of Shaanxi and the extreme west of modern Henan.
The average altitude of the Guanzhong Plain is around 500 metres. Xi'an, the capital of Shaanxi, is the largest city in the Guanzhong plain, which also contains the cities of Tongchuan, Baoji, Xianyang and Weinan.
The plain was the central region of the Qin during the Warring States period. Having fertile soil and good irrigation systems, Qin rose from this region to gain preeminece among the Warring States, and eventually unified China. Since the Zhou Dynasty, the area was the capital region of China for a total of 12 dynasties including the Han Dynasty, Sui Dynasty, and Tang Dynasty.

