The calculated distance (air line) between Retiro and San Nicolás de los Arroyos is approximately 136 miles respectively 218 kilometers.
By car or train, the actual journey to San Nicolás de los Arroyos is certainly longer, as only the direct route (as the crow flies) between Retiro and San Nicolás de los Arroyos has been calculated here.
Air line (approximately)
218 kilometers
118 nautical miles