Purple mist rushed in from the east to the city gates

It was built during the Qianlong period. The stone plaque on the south side is engraved with "Purple Qi Coming from the East", which is derived from the allusion of Lao Tzu leaving the customs, and the stone plaque on the north side is engraved with "Chicheng Xiaqi", which is derived from the famous sentence in the Jin Dynasty writer Sun Chuo's "Tiantai Mountain Fu". The city gate is not only a point view building, but also a pass for the defense of the park in that year.