Guyang County lies in the Western part of the Daqing Mountain range of the Inner Mongolia Plateau. Mountains and hills account for 90% of the county's total area. Guyang is especially famous for its ruins of the Qin GreatWall, the best protected section from the Qin Dynasty (BC221-BC206).The section extends 85 kilometers along the rise and fall of the Yinshan Mountain range, which offers a spectacular landscape alongside its long history. However, many sections of the ruins have been severely damaged due to geological changes, weather erosion and farmland encroachment. In some areas the ruins are hardly recognizable.