Beyond the Great Wall like a dragon, winding, the cross between heaven and earth. According to "the Great Wall of Ming Dynasty Huaxiazi examination" set: the Great Wall by the side of the town of Fort Yanggao County, about 4 kilometers west of Datong yuan Dun Cun field, enter the the Great Wall in Datong City, the basic trend is: by Yuan Dun West by the town of Kawaguchi Hiro. And then divided into two, the main the Great Wall by the Hong Fort thanks turns to the north, the East kiln, cross Yinma River, West to the town of Qiang Bao Zhen Qiang Bao, and by the wall, door, mouth to refuse help Ma to thirteen side by side, thirteen the Great Wall to the South to brick Lou Gou to the south, Datong in Zuoyun a county boundary. Another by the Hong Fort thanks to the habit, a new wing, break Lu Wu Shih border Zuoyun into the kiln. Datong municipal two north-south about 105 kilometers of the Great Wall.