The calculated distance (air line) between Káto Achaḯa and Petroúpolis is approximately 116 miles respectively 187 kilometers.
By car or train, the actual journey to Petroúpolis is certainly longer, as only the direct route (as the crow flies) between Káto Achaḯa and Petroúpolis has been calculated here.
Air line (approximately)
187 kilometers
101 nautical miles