Dasan Pass (simplified Chinese: 大散关; traditional Chinese: 大散關; pinyin: Da San Guān; literally: "Great Dissolve Pass") is a mountain pass located west mountain area of the city of Baoji in Shaanxi province.
It was a military mountain gate guarding the Guanzhong Plain since Zhou Dynasty. Because of it strategic location, more than 70 battles had been fought through Chinese history. In year 1131, Sony Dynasty general Wu，jie and Wu，lin brothers stationed here against Jin general Wanyan Wulu.
References
Da san pass Wikipedia(Text) CC BY-SA