The calculated distance (air line) between Gwangju and Yangp'yŏng is approximately 164 miles respectively 265 kilometers.
By car or train, the actual journey to Yangp'yŏng is certainly longer, as only the direct route (as the crow flies) between Gwangju and Yangp'yŏng has been calculated here.
Air line (approximately)
265 kilometers
143 nautical miles