The calculated distance (air line) between Sŭngho 1-tong and Kwaksan is approximately 68 miles respectively 109 kilometers.
By car or train, the actual journey to Kwaksan is certainly longer, as only the direct route (as the crow flies) between Sŭngho 1-tong and Kwaksan has been calculated here.
Air line (approximately)
109 kilometers
59 nautical miles