Munsusan Fortress defended the mainland side of the Ganghwa channel

Munsusan Fortress follows the mountain ridge and valley above the Ganghwa channel, guarding crossings and the Tongjin mainland. Built in the Joseon period and later repaired, damaged and restored, it cannot be reduced to the 1866 French campaign or treated as an untouched original. Gates, ridge walls and valley routes had different roles, supported by quarrying, transport, provisions and watch duty. Use official excavation and restoration information instead of judging stonework by appearance. Remain on the trail, do not climb unstable walls, and record the start point, elevation and route. Comparing its view with Deokpojin clarifies two different layers of coastal defence.