The calculated distance (air line) between Cheongsong gun and Hwawŏn is approximately 54 miles respectively 86 kilometers.
By car or train, the actual journey to Hwawŏn is certainly longer, as only the direct route (as the crow flies) between Cheongsong gun and Hwawŏn has been calculated here.
Air line (approximately)
86 kilometers
47 nautical miles