The calculated distance (air line) between Sangsŏng-ni and Hyesan-dong is approximately 168 miles respectively 271 kilometers.
By car or train, the actual journey to Hyesan-dong is certainly longer, as only the direct route (as the crow flies) between Sangsŏng-ni and Hyesan-dong has been calculated here.
Air line (approximately)
271 kilometers
146 nautical miles