Gansu lies between the Tibetan Plateau and the Loess Plateau, bordering Mongolia (Govi-Altai Province) to the northwest, Inner Mongolia and Ningxia to the north, Shaanxi to the east, Sichuan to the south, and Xinjiang to the west. The Yellow River passes through the southern part of the province. The province contains the geographical centre of China, marked by the Center of the Country Monument at . Part of the Gobi Desert is located in Gansu, as well as small parts of the Badain Jaran Desert and the Tengger Desert. The Yellow River gets most of its water from Gansu, flowing straight
Taklamakan Desert to regard the Taklamakan Desert as separate and independent from the Gobi Desert region to its east. The People's Republic of China has constructed two cross-desert highways. The Tarim Desert Highway links the cities of Hotan (on the southern edge) and Luntai (on the northern edge), and the Bayingol to Ruoqiang road crosses the desert to the east. In recent years, the desert has expanded in some areas, its sands enveloping farms and villages as a result of desertification. The Golmud-Korla Railway (presently, under construction; expected completion time, 2019) will cross the Taklamakan as well. Because it lies in the