三中三公式表图片简介:In front of Laiyuan Fort is the side wall of the Great Wall. On both sides are the towering Taiping Mountains. In the middle is a narrow West Border Gate, later called Xiaojing Gate, which is the only passage in and out of the Great Wall in the Zhangjiakou area.
In front of Laiyuan Fort is the side wall of the Great Wall. On both sides are the towering Taiping Mountains. In the middle is a narrow West Border Gate, later called Xiaojing Gate, which is the only passage in and out of the Great Wall in the Zhangjiakou area.