Guanzhong (
Kwanchung; ), or
Guanzhong Plain, is a historical region of China corresponding to the lower valley of the
Wei River. It is called Guanzhong or 'within the passes', as opposed to 'Guandong' or 'east of the pass', i.e., the
North China Plain. The North China Plain is bordered on the west by mountains. The
Yellow River cuts through the mountains at the
Hangu Pass separating Guanzhong from Guandong.