洪武五年的一天，朱元璋在读《孟子》，读着读着，朱元璋眉头越皱越紧。终于，把书一摔，大声说：“使此老在今日，宁得免焉？”立

JIayu Pass,was founded in five-year of Ming Emperor Hongwu (1372 AD),it was named after JIayu mountain which the pass was built along the west foot of,Jiayu pass was founded 9 years earlier than Shanhai Pass.Here is difficult terrain,with snowcapped Qilian mountain to its south,and rugged Hei mountain to its north,there is only 30 li's distance between Hei mountain and Qilian mountain,the location of Jiayu Pass is the narrowest section of Hexi Corridor,and is entitled "The first mountain pass in Hexi".To the west of the pass,there is a historic battlefield,to the east of the pass,there is jiuyan spring- lake,the lake is always clear and never dry.
After Great Zhengxi General of Ming Emperor--Fengzheng recovered Hexi,he decided to site the pass at the current location,and began the construction.186 years passed,a magnificent pass stands out at the chock point on the Silk Road.The pass has reasonable layout,proper construction,and servers the purpose of warfare defence.The pass has triple enceintes,multiple lines of defence,inner walls were built in the city,ditches were dug outside the city,this had formed the situation of multiple city walls and coordinated defences.In case of the intrusion of the enemy,the defenders could ensure safety.