Currency question

Yes the Euro

Thanks for the reply. I saw something online about a currency called "Eusko".

The Eusko is a valid local currency in the Basque region, but no one would expect a tourist to use it, and no one will turn down euros. Should add, you likely will not even see a Eusko.

Glad I’m not expected to use it. Just want to be sure.

Golly. This is news to me! I had no clue, and I've spent 12 nights in the Basque Country visiting both sides of the border.

Iys fixed to the euro. Get a few for souvenirs. More on that and similar: https://en.m.wikipedia.org/wiki/Complementary_currency

I did this tour last September and rarely used cash, most places these days accept mobile payments and cash is mostly used for street vendors or small souvenir shops that prefer cash. Counting the tour plus two nights in Paris beforehand and one extra night in Bilbao after I think I spent €150 in cash.