The calculated distance (air line) between Sŭngho 1-tong and Munsan is approximately 90 miles respectively 144 kilometers.
By car or train, the actual journey to Munsan is certainly longer, as only the direct route (as the crow flies) between Sŭngho 1-tong and Munsan has been calculated here.
Air line (approximately)
144 kilometers
78 nautical miles