Jeongbuk-dong Earthen Fortress is a Three Kingdoms-period fortification in northern Cheongju. It is one of the larger ancient earthen fortresses in the region and preserves the shape of an early defensive site rather than later stone walls.
The site is worth a stop for travellers interested in Korean archaeology and early military history. It is less polished than Cheongju's main museums, but its scale and age make it more than a routine local ruin.