The calculated distance (air line) between Songwŏn and Changam-ch’on is approximately 153 miles respectively 247 kilometers.
By car or train, the actual journey to Changam-ch’on is certainly longer, as only the direct route (as the crow flies) between Songwŏn and Changam-ch’on has been calculated here.
Air line (approximately)
247 kilometers
133 nautical miles