Earthen Fortification in Jeongbuk-dong (청주 정북동 토성)

The Earthen Fortification in Jeongbuk-dong was built around the third century BC on a flat land next to the Mihogang River. Its original square shape, with a perimeter of 650 meters, remains well-preserved, featuring gate remnants on the east, west, south, and north sides. The south and north gates include offset walls, designed to prevent enemies from entering directly. The protruding sections at the four corners and midpoints of the walls were strategically built for attacking and monitoring enemies from the sides.