The calculated distance (air line) between Basauri and Arrasate / Mondragón is approximately 23 miles respectively 38 kilometers.
By car or train, the actual journey to Arrasate / Mondragón is certainly longer, as only the direct route (as the crow flies) between Basauri and Arrasate / Mondragón has been calculated here.
Air line (approximately)
38 kilometers
20 nautical miles