Situated near the common boundary of Gansu, Qinghai and Xinjiang, the historical city Dunhuang is a renowned tourist destination, famous for the Mogao Caves. The landform of this area is a declining basin-plain from west to northeast, high in the north and south, and low in the middle, with Mt. Qilian in the south, Mt. Mazong in the north and desert from east to west. In ancient times, Dunhuang was the trade center between China and its western neighbors. At that time, it was the most westerly frontier military garrison in China. With the flourishing of trade along the Silk Road, it was prompted to become the most open area in international trade in ancient Chinese history. It provided the only access westward for the Chinese Empire and eastward for western nationalities. Today, as a reminder of this historical area, we are left with the Mogao Caves, Yangguan Pass, Yumenguan Pass and many wonderful Chinese poems depicting the time. As a city in desert, sandstorm usually happens, so prepare glasses, hats and gauze kerchiefs to protect you. The best visiting time is from May to September.