The calculated distance (air line) between Hoemul-li and Hyesan-dong is approximately 77 miles respectively 124 kilometers.
By car or train, the actual journey to Hyesan-dong is certainly longer, as only the direct route (as the crow flies) between Hoemul-li and Hyesan-dong has been calculated here.
Air line (approximately)
124 kilometers
67 nautical miles