Guyuan is a prefecture-level city located in the southernmost section of the Ningxia Hui Autonomous Region in the People's Republic of China. It borders the Gansu province to its east, south, and west. Historically, the city was known by the names Xihaigu or Dayuan.
The region is notable for housing the Mount Sumeru Grottoes (须弥山), which is recognized as one of the ten most famous grottoes in China. As of late 2024, Guyuan had a resident population of approximately 1,140,800, with roughly 46.95% of that population residing in urban areas.