\'The myth of Celtic and Roman Britain\'

[Alanus]

Totally agreed. My point though is that even the Romans who for much of their history were essentially landlubbers saw the ease and necessity of transport by water; for residents of ancient Atlantic Europe, travel by water would have made just as much if not more sense. Hence, I don't think it is crazy to assume that some kind of connection between ancient northern Spain and Ireland occurred , whereas contact between northern Spain and geographically closer regions in say central Gaul were more problematic and less frequent.

Not just sea-borne interaction between Spain and Ireland, but also southwestern Britain (to sneak the original subject in) where we find Tacitus' "swarthy" Silures. And it does seem to stop in coastal-central Gaul at Burgidalia and its major river. Beyond this point we have Biturigia, an extension of a central Gallic tribal group. Ausonius-- a son of Bordoux-- once said his childhood nanny was called "Maura" due to her dark features.

Transportation by water was accomplished up and down rivers, not just the ocean or "frog pond," and we see this particularly in routes that extended from the Rhine, then across a short portage, to the Danube and then on down to the Black Sea. From the Black Sea, we went north upon rivers to the Baltic along the "Amber Road." All of it connected people in far more than just trade goods.