The calculated distance (air line) between Samjiyŏn-ŭp and Manp’o is approximately 114 miles respectively 184 kilometers.
By car or train, the actual journey to Manp’o is certainly longer, as only the direct route (as the crow flies) between Samjiyŏn-ŭp and Manp’o has been calculated here.
Air line (approximately)
184 kilometers
99 nautical miles