Emperors held annual ceremonies to pray to heaven for a good harvest at the Temple of Heaven,Tiantan.It was built in Beijing in 1420. Emperors pray to heaven for good harvest.Ancient Chinese believed that Earth was Square and heaven was round.The altars and palaces were built into circles to represent heaven. The southern wall was rectangular to represent Earth.Chinese show their respect to heaven in Tiantan.
The Blue-glazed tiles of the imperial vault of heaven represent heaven.The circular mound altar is surrounded by a ring of nine plates,which are also surrounded by multiples of nine plates. It represents the supremacy of heaven.Tiantan covers an area of 2.7 million square meters,with an orderly arrangement showing Chinese regality.