Founded in the early Yuan Dynasty, it is the oldest existing Observatory in China. Guo Shoujing, composed of the observatory body and Shigui, is preparing to build and preside over the observation of stars for 365.2425 days a year. It is the most precise value used in Chinese and foreign history. The Observatory observes astronomical phenomena in Zhougong Temple during the Spring and Autumn Period to guide farming, which is closely related to the formulation of ancient Chinese calendar law. At present, this scenic spot is being maintained.