天坛位于北京城南端，始建于明永乐十八年（公元 1420 年），是明清两代皇帝祭祀天地之神和祈祷五谷丰收的地方。是中国现存的,最大的祭坛建筑群，天坛东西长1700米，南北宽1600米，总面积为273万平方米，包括圜丘和祈谷二坛，围墙分内外两层，呈回字形。北围墙为弧圆形，南围墙与东西墙成直角相交，为方形；这种南方北圆，通称“天地墙”，象征古代“天圆地方”之说。主要建筑在内坛，圜丘坛在南、祈谷坛在北，二坛同在一条南北轴线上，中间有墙相隔。圜丘坛内主建筑有圜丘坛、皇穹宇等等，祈谷坛内主要建筑有祈年殿、皇乾殿、祈年门等。
天坛建筑的主要设计思想就是要突出天空的辽阔高远，以表现“天”的至高无上。天坛还处处展示着中国传统文化所特有的寓意、象征的表现手法。北圆南方的坛墙和圆形建筑搭配方形外墙的设计，都寓意着传统的“天圆地方”的宇宙观。同时，她也是中国木结构建筑的顶峰，仅凭木榫交结，斗拱支架，全用木材就完成了这一惊世杰作。
Temple of Heaven (or Altar of Heaven), situated in southeastern urban Beijing (about 6 km away from the center), was built in 1420 during the Ming Dynasty to offer sacrifice to Heaven, and was thereafter visited by all subsequent emperors of the Ming and Q-
ing dynasties. Each Winter Solstice the emperor and all his retinue would move through the city to encamp within the complex, wearing special robes and abstaining from eating meat; there the emperor would personally pray to Heaven for good harvests. The Temple of Heaven is enclosed with a long wall. The northern part within the wall is semicircular symbolizing the heavens and the southern part is square symbolizing the earth. The northern part is higher than the southern part. This design shows that the heaven is high and the earth is low and the design reflected an ancient Chinese thought of ‘The heaven is round and the earth is square’.
The number nine represents the Emperor and is evident in the design of the Circular Mound Altar: a single round marmor plate is
surrounded by a ring of nine plates, then a ring of 18 plates, and so on for a total of nine surrounding rings, the outermost having 9x9
plates.
All the buildings within the Temple have special dark blue roof tiles, representing the
Heaven. The Seven-Star Stone Group, east of the Hall of Prayer for Good Harvest, represents the seven peaks of Taishan Mountain, a place of Heaven worship in classical China.
