Introduction to Changle Gate: Zhengding City was built in the Northern Zhou Dynasty and was renovated and completed in the fourth year of Wanli (1576). It has four city gates: East Yingxu, South Changle, West Zhenyuan, and North Yong'an, all with moon signs. City and barbican city. After years of wear and tear, only the ruins of the ancient city wall of Zhengding and three crumbling gates in the south, west and north remain.