The shape of Zhengding City is a bit special, its overall shape is directly south and north, basically square, but its eastern wall is straight, the western end of the north wall is slightly outward and not obvious, the western wall is generally a straight line, but the southern half of the turn out a few small bends like waves, only the southern wall is the most special, The southeast corner is recessed into a large square, the south west side of the city wall is a clear arc, from the height of the upper right corner is like a round "convex" word.