The calculated distance (air line) between Kowŏn-ŭp and Yonggang-ŭp is approximately 105 miles respectively 170 kilometers.
By car or train, the actual journey to Yonggang-ŭp is certainly longer, as only the direct route (as the crow flies) between Kowŏn-ŭp and Yonggang-ŭp has been calculated here.
Air line (approximately)
170 kilometers
92 nautical miles