The symmetrical layout of the Temple of Agriculture and the Temple of Heaven reflects the respect and emphasis on etiquette in traditional Chinese capital planning. As the largest existing royal place for worshipping the god of agriculture in ancient China, the Temple of Agriculture demonstrates the respect for farming culture in traditional Chinese society and carries the ritual tradition of worshipping the god of agriculture in the Ming and Qing dynasties. The Book of Rites: Sacrifice records: "The emperor personally ploughed in the southern suburbs to provide for the prosperity of the country." The Temple of Agriculture is located in the southwest corner of the outer city of Beijing's old city. Its location follows the tradition of personally ploughing in the southern suburbs. The Temple of Agriculture and the Temple of Heaven are symmetrically arranged from east to west along the central axis of Beijing. The Temple of Agriculture is divided into the inner and outer altars. The inner altar is located to the south and west of the outer altar and is a rectangular courtyard. The Taisui Hall complex located on the central axis of the inner altar, and the Temple of Agriculture, Jingtian and Guangengtai to the south are the main places for worship. The inner altar also has three groups of facilities serving sacrificial activities, namely the Shencang complex to the east of the Taisui Hall, the Shenchu complex to the west, and the Jufu Hall to the south. The outer altar wall was historically in the shape of a circle in the north and a south in the south, similar to the Temple of Heaven. The outer altar also has the altar of gods on the south side of the inner altar and the Qingcheng Palace on the east side of the inner altar. The main altars in the Xiannong Altar are all square in plan, which contrasts with the circular planes of the Circular Mound Altar and the Altar of Prayer for Good Harvests in the Temple of Heaven, forming two groups of national sacrificial buildings that are symmetrically arranged along the central axis of Beijing and contrast in architectural form. The inner altar of the Xiannong Altar is a ritual space for worshiping Tai Sui and Xiannong, and it is also the place where the emperor personally ploughs. The outer altar includes the altar of gods for worshiping gods of heaven and earth and the Qingcheng Palace used as a fasting palace. The worship of Xiannong is an important part of traditional Chinese national rituals, showing the importance that ancient Chinese society attached to agricultural activities and farming culture. In the Ming and Qing dynasties, the core objects of worship in the Xiannong Altar were the God of Agriculture (Emperor Yan Shennong) and Tai Sui Sui Jiang (the god of the year and the god of guarding the twelve months). According to legend, Shennong was the first person to teach Chinese ancestors how to cultivate land and grow grains. To thank him, his descendants worshipped him as a god and prayed for agricultural abundance. During the sacrifice to Shennong, the emperor not only had to worship Shennong, but also had to plow the land himself, promote the spirit of valuing agriculture and encouraging farming, and watch the princes and ministers plowing the land. The sacrificial activities at the Xiannong Temple continued until 1911. Today, the Xiannong Temple is open to the public as a museum, displaying ancient Chinese architecture and the sacrificial traditions of the Xiannong Temple. The Xiannong Temple was first built in the 18th year of the Yongle reign of the Ming Dynasty (1420). When it was first established, the altar had core ritual spaces such as the Xiannong Temple, the Taisui Hall, the Worship Hall, and the Fentian. In the second year of the Tianshun reign of the Ming Dynasty (1458), the Zhai Palace (now the Qingcheng Palace) was added. In the 10th year of the Jiajing reign (1531), the altars of the gods of heaven and earth were built on the south side of the Xiannong Temple, and a wooden viewing platform was built to the north of the Fentian for the emperor to watch plowing. In the 18th year of Emperor Qianlong's reign in the Qing Dynasty (1753), the altar of Xiannongtan was rebuilt, and the wooden viewing platform was replaced with a brick one. In 1915, the north side of the outer altar of Xiannongtan was opened to the public as a park, and was renamed Chengnan Park in 1918. In 1991, the Beijing Ancient Architecture Museum was established in Xiannongtan.