The calculated distance (air line) between Wŏnsan and Sŭngho 1-tong is approximately 79 miles respectively 128 kilometers.
By car or train, the actual journey to Sŭngho 1-tong is certainly longer, as only the direct route (as the crow flies) between Wŏnsan and Sŭngho 1-tong has been calculated here.
Air line (approximately)
128 kilometers
69 nautical miles