When were the 24 white marble pillars beside the moat at the south gate of the Temple of Heaven built?

2009165438+1October 7, 2009, in beginning of winter, 24 white marble pillars rose from Yongdingmen to the north bank of the south moat at the south gate of the Temple of Heaven in Beijing. The pillars were carved with the historical origin of each solar term in 24 solar terms.

Before and after Tiananmen Square, there are a pair of white jade pillars called Huabiao, also called watchtower. The stone utensils on the Chinese watch are very interesting. They are called "go out with the emperor" and "come back with the emperor". The purpose of "go out with the emperor" is to hope that the emperor will not stay in the palace all the time, and go around the people more to understand their sufferings.