Introduction to Mancheng: It was built in the 37th year of Qianlong reign of the Qing Dynasty (1772) to station Manchu banner soldiers, hence its name. At the end of the 19th century, the flag soldiers withdrew, leaving the city empty, houses demolished, and city walls collapsed. The city wall has a circumference of 3 kilometers and a height of 6.6 meters. It originally had 4 gates, four turrets, 12 forts, 1161 crenellations, and four small castles built on each of the four gates.