Study area (IMAGE) IGSNRR CAS Caption (a) Location of the Ordos Plateau; (b) Aerial photograph from the southern side of Shi-Er-Lian-Cheng (an ancient city which has been occupied for the longest time in the Ordos Plateau); (c) De- tailed satellite image of the Ordos Plateau (Google Earth, 2010). The purple line marks the location of the Ming Great Wall, and the yellow stars represent the following ancient cities: 1, Tiezhuquan; 2, Zhangjiachang; 3, Bayanhurihu; 4, Tongwan city; 5, Shi-Er-Lian-Cheng. Credit Journal of Geographical Sciences Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.