The actual control of the dividing line between Sun Moon Mountain and Datang and Tubu is also the dividing line between the Loess Plateau and the Qinghai-Tibet Plateau. In the beautified legend, Princess Wencheng broke the sun and moon treasure mirror here, farewelled her hometown, and entered Tibet without looking back. As a historical and geographical double legendary attraction, The tourists are pitiful, here the blue sky is washed, thousands of years under, throw can see the 14-year-old girl looking back at Chang'an