Master architect, come in! In what way does the Temple of Heaven architecture embody the theme of offering sacrifices to heaven?

The Temple of Heaven is divided into an inner altar and an outer altar by a double altar wall, which looks like the word "Hui". The south corner of the double altar wall is a right angle, and the north corner is an arc, symbolizing "a round place". All the palaces and altars face south in a circle, symbolizing the sky.

Ball altar is the place where the emperor holds gifts to worship heaven. It was built in the 9th year of Jiajing (1530). The altar is circular in plane and divided into three layers, all with white marble railings. The surface of the altar was originally made of blue glazed tiles. After being rebuilt in the 14th year of Qianlong (1749), it was paved with hard and durable mugwort bluestone. The circular mound altar has two low walls, the outer and inner circles, symbolizing a round place. Standing on the boulder in the middle of the top floor of the ball altar, although whispering, it is very loud. So whenever the emperor sacrifices to heaven here, his loud voice is like an Oracle from heaven, and the solemn atmosphere during the sacrifice is even more mysterious. This is because the surface of the altar is smooth, and the sound wave can quickly spread in all directions, hitting the surrounding stone fence, reflecting back and merging with the original sound, so the volume is doubled.

The altar of praying for the valley is the place where Meng Chun holds the ceremony of praying for the valley. It was built in the 18th year of Yongle in Ming Dynasty (1420). The main buildings include the Hall of Prayer for the New Year, the Palace, the East-West Annex Hall, the Gate of Prayer for the New Year, the Chef, the Sacrificial Pavilion and the Promenade. The altar for praying for the valley is a circular building with a combination of altar and temple, which was established according to the ancient saying that "His Highness offered sacrifices to the emperor". The altar has three floors, with a height of 5.6m, a lower diameter of 9 1 m, a middle diameter of 80m and an upper diameter of 68m.

The Hall of Prayer for the New Year is circular, with a height of 38 meters and a diameter of 32.7 meters. It has three layers of blue glazed tiles, round eaves, pyramid-shaped roofs and gilded roofs. Twenty-eight nanmu columns and thirty-six connected table rafters support the three-story temple eaves. These big pillars have different symbolic meanings: the four pillars in the middle are called Tian Tongzhu, representing the four seasons; Twelve gold pillars in the middle layer represent twelve months; Twelve eaves columns on the outer layer represent twelve o'clock; Twenty-four solar terms are expressed by adding the middle layer and the outer layer; The three layers add up to 28, representing 28 stars; Add eight sub-columns at the top of the column, representing thirty-six days; The Leigong column under the top of the treasure represents the emperor's unification of the whole country. Its ancillary buildings include the Imperial Palace, the gate for praying for the New Year, the God Library, the God Chef, the sacrificial pavilion, the wood stove, the coffin pit, the service platform, the sacrificial road and 72 long corridors. There is a seven-star stone in the square to the south of the promenade, engraved with mountain-shaped moire, which was placed in the Jiajing period of Ming Dynasty.

Huang Gan Hall is located in a rectangular courtyard, surrounded by a wall connected by glass doors, which is used to pray for the New Year. This is a temple-style hall, covered with blue glazed tiles, with the base of white marble railings below. It is a temple dedicated to the "God of the Emperor" and the ancestors of the Emperor. God's slate is enshrined in a shrine shaped like a house. On the first and fifteenth day of the lunar calendar, the yamen responsible for offering sacrifices regularly sends officials to sweep away dust and burn incense. The day before the sacrifice, after the emperor came here to burn incense and salute, the minister of rites burned incense, and then he knelt down three times and knocked nine times. Then the officials of Taichang Temple headed by Qing asked them to put the tablet in Long Ting, and it was carried to the corresponding shrine in the Hall of Prayer for the Year by Yi Wei Er.

The Ball Altar, the Imperial Dome and the Valley Prayer Altar are three main buildings on the central axis. Connecting these three main buildings is a long platform running through the north and south, which is called Single Pen Bridge, also known as Shinto or Seaview Avenue. It is 360 meters long, 29.4 meters wide and 1 meter high at the southern end. It gradually rises to 3 meters from south to north, symbolizing that this road is connected with the Tiangong, and the emperor ascended to heaven step by step from south to north. In the middle of the single bridge is Shinto, on the left is Imperial Road, and on the right is King Road. The emperor takes the imperial way, the ministers take the kingly way, and the immortals take the Shinto way. There is an east-west tunnel under the bridge, which is the hole where livestock are sent to be slaughtered before sacrifice.

The main design idea of Tiantan architecture is to highlight the vastness and height of the sky to show the supremacy of "heaven". In layout, the inner altar is located on the east side of the north-south central axis of the outer altar, while the ball altar and prayer altar are located on the east side of the central axis of the inner altar. These are all to increase the openness of the west, so that people can gain a broad vision after entering the Temple of Heaven from the main entrance in the west, and thus feel the greatness of heaven and its own smallness. As far as single buildings are concerned, the Hall for Praying for the New Year and the Royal Hall both adopt circular pyramid roofs, and their external bases and eaves shrink and rise layer by layer, which also reflects a feeling of being close to the sky.

The Temple of Heaven also displays the unique meaning and symbolic expression of China traditional culture everywhere. The altar wall and outer wall in the south of the North Circle are square and circular architectural design, which symbolizes the traditional world view of "the sky is round and the place is round". The widespread use of blue glazed tiles in major buildings, as well as the "Yang Shu" in the altar and the design of columns in the Hall of Prayer for the New Year are also concrete manifestations of this expression.

(The above contents are recorded in the "Temple of Heaven" entry of Baidu Encyclopedia, and the related contents of offering sacrifices to heaven are slightly sorted out. )