The calculated distance (air line) between Sŭngho 1-tong and Songnim-ni is approximately 24 miles respectively 39 kilometers.
By car or train, the actual journey to Songnim-ni is certainly longer, as only the direct route (as the crow flies) between Sŭngho 1-tong and Songnim-ni has been calculated here.
Air line (approximately)
39 kilometers
21 nautical miles