The calculated distance (air line) between Ganghwa-gun and Gapyeong is approximately 56 miles respectively 91 kilometers.
By car or train, the actual journey to Gapyeong is certainly longer, as only the direct route (as the crow flies) between Ganghwa-gun and Gapyeong has been calculated here.
Air line (approximately)
91 kilometers
49 nautical miles