The calculated distance (air line) between Sinmak and Hwangju-ŭp is approximately 30 miles respectively 49 kilometers.
By car or train, the actual journey to Hwangju-ŭp is certainly longer, as only the direct route (as the crow flies) between Sinmak and Hwangju-ŭp has been calculated here.
Air line (approximately)
49 kilometers
26 nautical miles