Several problems about the westernmost end of the Great Wall in Ming Dynasty

The Great Wall of Ming Dynasty starts from the Yalu River in the east and ends at Jiayuguan in the west, and runs through 9 provinces, cities and autonomous regions such as Liaoning, Hebei, Tianjin, Beijing, Inner Mongolia, Shanxi, Shaanxi, Ningxia and Gansu, with a total length of more than 6,300 kilometers, commonly known as the "Great Wall of Wan Li".

The detailed records are as follows: ① The western Liaoning side wall was built in the seventh year of Ming Yingzong Orthodox (1442), and Wang Ao was the military affairs prefect of Liaodong. "Bows patrol the border, from Shanhaiguan to Kaiyuan, with high walls and deep trenches, five miles for castles, ten miles for tuns, peaks and mountains, and continuous pearls." (Record of the Whole Liao, Volume IV, Belief of Emperor Ming Cong, Volume XVIII) West of Changqi in western Liaoning, starting from the junction of the Great Wall of Jimingkou Town, Beizushan, Shanhaiguan, it extends northeast along the eastern slope of Xishan Corridor in western Liaoning to Baituchangguan (now Baichangmen Township, Heishan County, Liaoning Province). (2) The Liao River set up a side wall, which is recorded in "All Liao Annals and Frontier Annals". "When respecting Liaodong, mountains rise because of rivers, and wood is woven as a wall. For a long time, it is easy to use one wall, while the pier is slightly increased. " "After the border is established, Liaohe will be placed under the territory." In the early years (1506), Li was the governor of Liaodong. "Please build a wall, stretching for more than 500 miles from the north of Sancha River in Liaoyang to Kaiyuan." After many times of construction, the side wall of Liaohe River in the west is Guanshun on the west bank of Liaohe River, passing through the east moat of Heishan County, Dataizi and Liutaizi in taian county, crossing the Liaohe River in the northwest of Niuzhuang Town in Haicheng County, then turning to the northeast, along the east bank of Liaohe River to Kaiyuan and Changtu County, and ending at Zhenbeibao. Because the Great Wall is surrounded by a big V-shape to the south, it is located on the east and west banks of Liaohe River, so it is called "Liaohe Great Wall". (3) Liaodong side wall was built in Chenghua for three years (1467). After the Ming army drove out the Nuzhen in Jianzhou, Han Bin and Zhou Jun successively built Dongzhou to Caohe Ten Fort, Zhenbei Fort and Qingyang Fort for fifteen years (1479) and seventeen years (148655).