This fort was built in 1436 to protect the country from foreign invaders coming in attack from the north, and it was rebuilt in 1555 and 1739.

The rectangular fort is 4,500 meters in circumference and the height of walls is 3 meters at present, originally 4 to 5 meters.

In the fort there were four gates, three big ponds, a lot of wells, six pavilions, including Koyon Pavilion for archery practice, and commanding posts.

Preserved there are Inphung Pavilion, one of the eight scenic spots in the northwestern part of Korea, and Mangmi Pavilion.

The above-said historical sites have turned into a place for inhabitants' relaxation after being restored to their original state under the Workers' Party of Korea's policy of protecting national heritages.