Zuo Yintai Gate Site is the East Gate of Daming Palace.As the Jiacheng outside the gate was stationed by the Central Prohibit Army,it had a very important strategic position.In the history of Daming Palace,one of the dye-makers,Zhang Shao,entered the palace from the left silver gate one night and attempted to make trouble.He killed the guards at the palace gate and rushed to the Hall of Qing Si,north of the left Yintai Gate.Tang Jingzong,who was fighting in the Temple of Qing Si,heard the sound of killing and was terrified.He went to the nearby Left Army barracks to escape and escaped.Thus,Zuo Yintai Gate plays an important role in the security of Daming Palace.