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