Believed to be built in the period of Koguryo Kingdom (B.C. 277-A.D.668) and rebuilt in 1753, the fortress is nearly 4.1 kilometers round.

The construction method of the fortress is the same with that of the Walled City of Pyongyang and Rongori Fort built in the Koguryo period.

The fortress has four gates at the four cardinal points, with small gates between them.

In front of the south gate, there is a 25-meter-long fort.

There are ruined general's terraces in the northern, eastern and western parts of the fortress.

On Komunryong Peak, the highest place in the fortress, there is a site of general's terrace, while two other sites standing between the east and south gates and between the west and north gates.

Discovered in the fortress were lots of building sites and many pieces of tiles dating back to Koguryo Kingdom, Koryo Dynasty (918-1392) and Feudal Joson Dynasty (1392-1910).