The Loess Plateau starts from Qinling Mountain in the south, reaches Sun Moon Mountain in the west and Taihang Mountain in the east, covering 6 provinces of Qinghai, Ningxia, Gansu, Shaanxi, Shanxi and Henan, covering an area of 640,000 square kilometers. The thickness of loess cover is generally below 100 m, and the loess layer in Longdong, northern Shaanxi and western Shanxi is the thickest. From the east of Liupan Mountain to the west of Luliang Mountain, the thickness of loess is between 100 meters and 200 meters, and the thickest is in Lanzhou, reaching more than 300 meters. The area and thickness of loess are the highest in the world.

So Lanzhou is on the Loess Plateau.