The Sheji Altar is located in the southwest of the Forbidden City, close to the central axis and symmetrical with the Imperial Ancestral Temple. The building complex is a rectangular building complex that is slightly longer from north to south, and is surrounded by two inner and outer walls to form a ring-shaped courtyard. The inner altar is a ritual and sacrificial space, surrounded by a square inner wall in the center, with a door on each of the four sides of the inner altar wall and the inner wall, and the altar in the center. The God Storehouse and God Kitchen are located in the southwest corner of the inner altar, and the slaughter pavilion building complex is located outside the west wall. 612 ancient trees are planted in the outer altar, creating a quiet atmosphere of the royal altar. In addition, the outer altar area also creates a garden landscape with a strong Chinese traditional interest. There are two rockery in the west, and a free-form pond in the southwest. There are waterside pavilions, Tanghuawu and other buildings around the pond. The Sheji Altar is the most complete ceremonial building complex for the royal sacrifice to Taishe and Taiji in ancient China. The outer altar, inner altar, and inner triple altar walls create a sacred sacrificial atmosphere with rich levels of change. The inner altar is the core of the sacrificial space. From south to north, along the central axis of the inner altar, there are Nantanmen, Nanxingmen, Shejitan altar, Beilingxingmen, Baidian, Jimen, Beitanmen and other buildings. After entering the inner altar, you can see the inner wall. The center of the inner wall is the Shejitan altar. The north of the inner wall is the Baidian. Jimen is located directly north of the Baidian and is slightly lower than the Baidian. Beitanmen was the entrance to the ritual sacrificial route during the Ming and Qing dynasties, so it is taller than the South Gate. Shejitan was a place for worshiping She (land) and (grains) during the Ming and Qing dynasties. The significance of worshiping Sheji and Ji is not limited to the worship of land and grains themselves, but it shows the importance of the country's territory, and has the extended meaning of praying for the country's solid foundation, prosperity, and integrity of the territory. The worship of Sheji emphasizes the influence of land and grains on the country and society, thus closely linking the national and social order with the relationship between people and land. Shetan became a park in modern times. It is the earliest royal temple in Beijing to be transformed into an urban park, and it is still open to the public as a park. The Altar of Land and Grain was first built in the 18th year of the Yongle reign of the Ming Dynasty (1420). Initially, there was only an altar in the inner altar. In the Ming Dynasty, the slaughter pavilion, the god's storehouse and god's kitchen, the worship hall and the gate were successively built. The resulting structure has been preserved to this day. Only the main buildings were repaired in the Qing Dynasty. On October 10, 1914, the Altar of Land and Grain was opened to the public as the Central Park. It was the first royal temple in Beijing to be transformed into an urban park, and witnessed the process of the publicization of the central axis of Beijing. In 1928, the Central Park was renamed Zhongshan Park and is still open to the public today.