The calculated distance (air line) between Conakry and Donghol-Sigon is approximately 185 miles respectively 298 kilometers.
By car or train, the actual journey to Donghol-Sigon is certainly longer, as only the direct route (as the crow flies) between Conakry and Donghol-Sigon has been calculated here.
Air line (approximately)
298 kilometers
161 nautical miles