Introduction to the North Great Wall: The North Great Wall, commonly known as the Dawukou Great Wall, was built in the 10th year of Jiajing in the Ming Dynasty (1531 AD). The Great Wall runs from Shahu to Zaoshan Valley in Helan Mountain, with a total length of 35 miles, east to west. Along the way, there are three beacon tower ruins, one Linshan Fort ruins and one Beimenguan ruins.