Shanxi Changzhi City, why is called on the party?

Shangdang, "Interpretation of Names" said, "Party, also, in the mountains where it is the highest, so it is called Shangdang also." The Shangdang area mainly refers to today's Changzhi City, which is an upland area surrounded by mountains. Its east is the Taihang Mountains, and today's Hebei, Henan Province; west is the Taiyue Mountains and Linfen border; north of Wuyun Mountain, Bafu Ling and other mountains and Jinzhong border. To the south are Danzhuling and Jinquan Mountain adjacent to Jincheng. The party area is high and dangerous, since ancient times for the strategic location, Di Ziqi "National Policy on the name of the exam" said "the ground is very high, and the sky for the party, so it is called on the party", the meaning of which is this.