第四道就是外城了。
Chaoyang city's urban form is divided into outer city and inner city.朝阳古城的城市形态主要分为外城和内城。
The outer city wall was built in 1680 to protect the urban area outside the inner city wall, which also had eight gates.外城墙建于1680年,以保护城市地区以外的内城墙,这也有个大门。