Construction of the Temple of Heaven was begun in the year 1406 during the reign of the Ming Emperor Yongle. It took 14 years to complete. It was later expanded under the Qing emperors Qianlong (1736-1796) and Jiaqing (1796-1820). The area of the Temple of Heaven is more than twice that of the Imperial Palace, occupying 2,668 hectares, or about 6,670 acres. The three main structures used in the sacrifices are circular, corresponding to the supposed shape of Heaven. The glazed tile roofs of the buildings are deep blue and the platforms constructed of slabs of white marble. Each of the three platforms consists of three tiers, making a total of nine tiers-nine in Chinese cosmology representing Heaven. The number and layout of every single slab used in the platforms is determined according to cosmological principles.

Originally the Temple of Heaven had only one main gate, which faced west, but after it was made a public park in 1949, entrances were also opened on the northern, southern and eastern sides. The Bridge of Cinnabar Steps (Danbiqiao), a 360-meter-long stone walkway, connects the main architectural structures of the temple-the Hall of Prayer for a Good Year (Qiniandian) to the north and the Hall of the Imperial Heavenly Vault (Huanqiongyu) and the Altar of Heaven (Huanqiu) to the south.

The section of wall enclosing the southern end of the temple grounds is square, while that in the Northern end is semi-circular, based on the ancient notion that the Earth is square and Heaven round. Old cypress trees surround the buildings, creating an appropriately spiritual atmosphere. The Temple of Heaven has two walls with inner and outer sections, inner reserved for important sacrificial structures and the outer occupied by auxiliary buildings.

On the day before sacrifices were to be conducted, the emperor came to the temple to perform preliminary rituals. He spent the night fasting in the Hall of Abstinence, directly east of the Bridge of Cinnabar Steps. This square hall is surrounded by a moat and high wall. Aside from the main hall, sleeping quarters, watch room and bell tower, there is a small stone pavilion with a bronze statue. The statue holds a plaque inscribed with “Rules of the Fast” to remind the emperor of his task. Legend holds that the statue is modeled after a Tang Dynasty official who was once bold enough to point out the emperor’s faults.

The Temple of Heaven also had an office of divine music to train musicians for the rituals as well as a sacrifice chamber where animals were prepared for sacrifice.

At the north end of the Bridge of Cinnabar Steps one passes through the Gate of Prayer for a Good Year into a large square courtyard, in the center of which is a circular marble platform of three tiers with steps leading up on four sides. An ornately carved white stone bound each tier railing. Both the railings and the large flat slabs separating each of the staircases are carved with dragons, phoenixes and cloud scrolls depicting the ascent of the dragon and the phoenix. In the center of the platform stands what is perhaps one of the finest examples of wooden Chinese architecture, the Hall of Prayer for a Good year. It was first built in 1420 and rebuilt according to the original plan as recently as 1890, after it was struck by lightning.

The circular Hall of Prayer for a Good Year has a three-tiered roof of sky-blue glazed tiles. The peak, some 38 meters from the ground, is crowned with a spherical gilt ornament. The pillars and brackets of the hall’s roof, 30 meters in diameter, are supported without a single nail. Of its 28 pillars, the four in the middle-the so-called Dragon Well Pillars-are 19.2 meters high. The other pillars, of Phoebe nanmu wood, are arranged according to the 12 months and the 12 time periods into which the day is divided. Each pillar is an enormous single tree trunk.

Set in the center of the flagstone floor is a round veined marble stone with a“found” pattern of a dragon and a phoenix. The hall has no actual walls, only frame doors all around. Twice a year the emperor came here to perform the most sanctified rituals of the empire. On the 15th day of the first lunar month, he sacrificed to ensure an abundant grain harvest. At the winter solstice, he expressed his gratitude for the blessings from Heaven.

The Hall of the Imperial Heavenly Vault at the southern end of the Bridge of Cinnabar Steps served as storehouse for the spirit tablet of the Supreme Ruler of the Universe (Huangtian Shangdi). When the ceremonies were conducted, the tablet was moved to the Altar of Heaven, located directly to the south of the Hall of the Imperial Heavenly Vault. During the sacrifices, worship was offered to the Supreme Ruler of the Universe, to the spirits of the sun, soon, stars, clouds, rain, wind and thunder, as well as to the emperor’s ancestors. During times of drought, prayers for rain were also offered here. The Hall of the Imperial Heavenly Vault stands 19.5meters tall and is 15.6 meters in diameter. It was first built in 1530 and restored in 1752. The interior retains its original splendid decoration. Surrounding the hall is a circular wall constructed of tightly fitted bricks. A gate opens to the south, leading to the Altar of Heaven.

The Altar of Heaven is constructed of three tiers of green and white marble, the circumference of each tier being fitted with a white marble balustrade. The surface of the platform, the stairs and the railings are made up of stone slabs in multiples of nine. This is drawn from the ancient Chinese belief that nine was the numerical epitome of Yang, the positive force, and symbolized Heaven. The top platform is 33.3 meters in diameter and has a circular stone in the center, which was considered the most sacred spot in the Chinese empire. The first ring of stones around it consists of nine slabs, the second ring of 18, the third of 27 and forth until we reach the ninth and outermost row which consists of 81 slabs. Like the top level, the central and lower levels are each made up of nine concentric rings of slabs which again being laid out in multiples of nine. Each tier has four approaches - one from each of the four directions- and the staircases at these points each have nine steps. To the southeast of the altar stands a glazed tile stove used for burning offerings of silk, and to the southwest is a“signal lantern platform.” When lit before dawn on winter days, these fires must have added a particular eeriness to the scene.

The construction of the Altar of Heaven was begun in 1530. It was rebuilt once in 1749. Because the sacrifices were made to Heaven, it was thought best to leave the structure open to the sky. Because a circle symbolizes Heaven, the platform is round. It is surrounded by two sets of walls; the outer square wall symbolizing Earth and the inner round wall symbolizing Heaven.

A person standing in the center of the altar who speaks softly will hear the echo of his own voice. Others on the platform will not hear it because the sound echoes off the surrounding balustrade and returns directly to the center of the circle. In addition, if one stands on the first flagstone at the bottom of the staircase which leads up to the southern entrance door of the Hall of the Imperial Heavenly Vault and claps or shouts loudly, a single echo is produced; standing on the second flagstone, a double echo is produced; and on the third flagstone, a triple echo can be heard. Also, in the same courtyard, if two people stand at the east and west extremes of the circular“Echo Wall ”and speak softly, the sound will be propelled around to the person on the opposite side.

Other items of interest in the Temple of Heaven are the bronze incense burner ornamented with the Eight Diagrams and the bronze tripod (ding) in front of the Hall of Prayer for a Good Year, the Hall of Imperial Heaven (Huangqiandian), the Divine Kitchen and the Seventy-two Corridors, as well as the gnarled Nine-Dragon Cypress, the intertwined cypress and locust trees, and the Seven Meteorites.