Introduction to the ancient castle: The ancient castle is the only intact ancient building among the 15 passes in Qianxi County. Except for natural collapse, there are few man-made damages. The height of Qingshan Pass is 1.8 feet, the gate is 1.4 feet, and its circumference is 166.9 feet. Founded in the Hongwu period of the Ming Dynasty, the Ming Dynasty buildings in the ancient castle include the Ming Dynasty Qianzongguan office, barracks, Qi Military Academy military field, Guandi Temple, inns, teahouses, wine shops, etc.