The calculated distance (air line) between Azpeitia and Gernika-Lumo is approximately 23 miles respectively 37 kilometers.
By car or train, the actual journey to Gernika-Lumo is certainly longer, as only the direct route (as the crow flies) between Azpeitia and Gernika-Lumo has been calculated here.
Air line (approximately)
37 kilometers
20 nautical miles