The calculated distance (air line) between Acilia-Castel Fusano-Ostia Antica and Ariccia is approximately 18 miles respectively 29 kilometers.
By car or train, the actual journey to Ariccia is certainly longer, as only the direct route (as the crow flies) between Acilia-Castel Fusano-Ostia Antica and Ariccia has been calculated here.
Air line (approximately)
29 kilometers
16 nautical miles