The calculated distance (air line) between Oñati and Arrasate / Mondragón is approximately 5 miles respectively 7 kilometers.
By car or train, the actual journey to Arrasate / Mondragón is certainly longer, as only the direct route (as the crow flies) between Oñati and Arrasate / Mondragón has been calculated here.
Air line (approximately)
7 kilometers
4 nautical miles