I've heard it said that the Basque are conjectured to be the last remnant of Pre-Celtic Western Europe. When would have these people existed? What evidence do we have for their culture and habitation sites? When did they cede to the Celts?
Pre-Celtic inhabitants of western Europe included Bronze Age settlers, such as the Lusitaninans, Basques, Belgians, and Etruscans.
Prior to that, we are talking about pre-historic cultures such as those that settled river valleys like the Dordogne in France.