Hall of Prayer for Good Harvests
This is the Hall of Prayer for Good Harvests, the main building in the compound.  It is a lofty cone-shaped structure with triple eaves, and the top is crowned by a gilded-ball. The 6-metre-high base of the structure is a triple-tiered circular marble terrace over 5,900 square metres in area. Each ring is balustraded in carved white marble. It gives the effect of lace when seen from a distance. The roof of the hall is made of blue glazed tiles, following the colour of the sky.
     The building is not only splendid in outer appearance, but also unique in inner frame.  Without the use of steel, cement and nails, even without the use of big beams and crossbeams, the entire structure--38 metres high and 30 metres in diameter--is supported by 28 massive wooden pillars and a number of bars,  laths, joints and rafters,  which are integrated into a reinforced frame to prop up the bulk of the Hall. The four central pillars, called the Dragon-Well Pillars, are 19.2 metres high, and so big that each will take two and a half men to encircle it with their arms stretched out. They represent the four seasons.  There are two rings of twelve pillars each, the inner ring symbolizing the twelve months and the outer ring the twelve divisions of the day and night. The pillars, 28 in number also represent the 28 constellations in the sky. The timber for making these pillars was shipped all the way from Yunnan Province in Southwest China.  The centre of the stone-paved floor is a round marble slab with a natural pattern of dragon and phoenix. On the right (east) there used to be two sets of screens, two chairs and a long table. The tablets of the emperor's ancestors were placed on the table, which is now on display.  On your left (west) the emperor used the chair to take a rest after the service.
     The day before praying for good harvests, the emperor came to the Hall of Imperial Zenith just behind this hall to present incense and then came here to inspect the tablets. The tablet of the God of Heaven was kept in the shrine while other tablets were placed on the stone platform. He then left by the left side gate for the Storehouse of the Gods to inspect sacrificial articles before he returned to the Hall of Abstinence.
      On the day of the prayer, the emperor worshipped the God of Heaven. Fire was built in the oven to usher in the God of Heaven.  The emperor presented white silk and three courses of dishes to the God. Finally, the silk and food were taken away, followed by music and dance.
    During the ceremony, the emperor stood on the dragon-and-phoenix marble, delivered a speech and tasted the offering food. The princes stood outside the hall, with the band, the dancers and officials standing on both sides.
    The hall has no walls, only partitions of open lattice windows. The ceiling is painted with fine colour drawings.  It was struck by lightning and burned down. In 1889 and was afterwards rebuilt according to its original design.
     Five thousand dragon designs are decorated on the inside and outside of the Hall of Prayer for Good Harvests. They are very sumptuous, and colours are natural and harmonious. They are suited to the occasion.
     The circular wooden hall is popular with photographers, owing to its unigue architectural style. But the interior framework is far more distinctive.
     On each wing of the main hall, there are subsidiary halls in which were worshipped the Gods of the Sun, the Moon and the Stars and the Gods of wind, Rain, Thunder and Lightning. Now the halls are used as gift shops. Going out of the gate of the Hall of Prayer for Good Harvests, visitors come to a raised passage 360 metres long, 30 metres wide and 4 metres high. This broad walk, called Red Stairway Bridge  connects the two sets of main buildings in the Temple of Heaven.
    In the middle of the passage there is a platform on the eastern side. This is where the emperor changed his clothes before going to worship.
    To the south lie the Imperial Vault of Heaven and the Circular Mound Altar. These three buildings are arranged in a straight line. An aerial view of the enclosure will show that the wall to the south is square while the one to the north is semi-circular. Such a pattern represents the ancient belief that heaven was round and the earth square.