The calculated distance (air line) between Cheongju-si and Gwangmyeong is approximately 67 miles respectively 109 kilometers.
By car or train, the actual journey to Gwangmyeong is certainly longer, as only the direct route (as the crow flies) between Cheongju-si and Gwangmyeong has been calculated here.
Air line (approximately)
109 kilometers
59 nautical miles