The calculated distance (air line) between Sŭngho 1-tong and Kaesŏng is approximately 77 miles respectively 124 kilometers.
By car or train, the actual journey to Kaesŏng is certainly longer, as only the direct route (as the crow flies) between Sŭngho 1-tong and Kaesŏng has been calculated here.
Air line (approximately)
124 kilometers
67 nautical miles