The calculated distance (air line) between Man’gyŏngdae-ri and Haeju is approximately 66 miles respectively 106 kilometers.
By car or train, the actual journey to Haeju is certainly longer, as only the direct route (as the crow flies) between Man’gyŏngdae-ri and Haeju has been calculated here.
Air line (approximately)
106 kilometers
57 nautical miles