1. Fu Xuan Town is now Xuanhua District, Zhangjiakou City, Hebei Province. It is one of the Jiubian towns established in the early Ming Dynasty. Named after the company commander stationed in Xuanhua Prefecture, it is also referred to as "Zhen Xuan".

2. The side wall under Fu Xuan's jurisdiction starts from Hayes House in Juyongguan in the east and ends at Xiyang River in Yanggao County in northeast Shanxi in the west, with a total length of 1023 Li.

3. Fu Xuan Town has always been a battleground for military strategists, and its strategic position is very important. Especially after the Ming Dynasty made Beijing its capital, Fu Xuan Town was the throat to defend Kyoto and resist the Mongols going south. Ming Cheng Daosheng said in the Nine Faces Textual Research: "There is a dispute between mountains and rivers in Fu Xuan, and the land is dangerous and narrow. Zizhai must be twice as big as other towns, so it is said that it is easy to defend because of the situation, but it is not 400 miles away from the capital, so we know the key."