Basque country is definitely on my to-visit list.
Every time I come on here I’m astounded by the geological photos!
I’m pretty sure the folding/faulting around the Basque is due to the Variscan Orogeny (mountain building period) when Euramerica and Gondwana collided to form Pangaea around 300 million years ago.
The fact that these beds are almost vertical gives you some idea of the forces that this period in geological history entailed.
Basque Country, Spain.