Founded in the Roman era, by Pompeii, or maybe founded in ancient times by the local people and named Iruña after the Basque word for 'city'.
This is Basque country, where the street signs are in both Castilian and Basque. This is the only language in Europe left over from before the Indo-Europeans arrived, but it's shrunk to a whisper of its former self. Most people here speak Castilian Spanish amongst themselves, with a particular Navarrese accent - with the z's and soft c's as subtle th's, but with the s's as strong sh's.