Introduction to the city wall: The inner city is mainly the past royal palace, consisting of government offices, residences of military and political officials, and Buddhist temples. The inner city is built from mounds from the feet up, forming a spectacular city tower with the same height as the mounds. Its architectural shape Exactly the same shape as the mound, which is wide at the top and narrow at the bottom, the city wall is made of mud and stone, and there are several outposts and forts built with adobe around it. There are gates around the city, among which the gate in the northeast corner is relatively well preserved.