The calculated distance (air line) between Gargaliánoi and Agios Dimitrios is approximately 130 miles respectively 209 kilometers.
By car or train, the actual journey to Agios Dimitrios is certainly longer, as only the direct route (as the crow flies) between Gargaliánoi and Agios Dimitrios has been calculated here.
Air line (approximately)
209 kilometers
113 nautical miles