Built in the ninth year of the Jiajing era of the Ming Dynasty (1530), it was commonly known as the "Heaven Terrace" because the Emperor held the "Heaven Worshipping Ceremony" on the platform every winter solstice. Initially, it was a blue glazed round platform, and was expanded in the 14th year of the Qianlong era (1749) in the Qing Dynasty to change the blue glazing into a Chinese white jade stone railing and an aye-green stone table top.

The number of stone steps, the stone table tops and the stone balustrades of the building are all in the multiples of "nine" and "nine" to correspond to the "nine heavens". The repeated use of "nine" emphasizes the supremacy of the heaven.

Translated by LIU Yu