This historic and impressive wall is one of the oldest, largest and best still preserved Chinese city walls, which was built under Emperor Honghu Qu Yuanchang as a military defense system for the city, and has been renovated several times since its construction in the 14th century, three times at intervals from about 200 years in the latter half of 1500 AD and 1700 AD, and in the later years in 1983. The wall covers an area of about 14 square kilometers. It was built in the Chinese architectural style, and was built as a defensive fortress with a moat, lookout bridges, corner towers, retaining walls and doors, and includes a corridor at the top where visitors can walk around and get acquainted with this historical wall.