The calculated distance (air line) between Hwangju-ŭp and Kangdong-ŭp is approximately 37 miles respectively 59 kilometers.
By car or train, the actual journey to Kangdong-ŭp is certainly longer, as only the direct route (as the crow flies) between Hwangju-ŭp and Kangdong-ŭp has been calculated here.
Air line (approximately)
59 kilometers
32 nautical miles