List of Celtic place names in Portugal
In the area of modern Portugal a significant number of towns with Celtic toponymic were already mentioned by ancient Greek and Roman authors. The regions where we can find a greater number of these names are in the north (inhabited by the Callaici or Callaeci) and center (inhabited by the Lusitanians) of Portugal.
Source: Wikipedia — List of Celtic place names in Portugal (CC BY-SA 4.0)