“Hoejinseong is the largest earthen fortification in the former area of Baekje, and it is 100m longer in circumfernce than Mongchontoseong in Seoul. The fortification is semi-enclosed with mountains to its east, west and north. Only the south is open, facing the Yeongsangang River.

The fortress wall is 2.4km in length, and the bottommost part is 14m in width. There are mountains that enclose the three sides of the valley. The steep cliffs were cut to create the fortress wall, and earth was piled to create a 6m x 6m wall along the valley. There are also traces of four gates that were built on the flat areas of the mountain ridge, and traces of floodgates in the low valley in the southern area.