Do you like rocks?

[VNwalking]

If you are walking:
The initial stages of the Frances
The Baztanes
The Vasco Interior or the Via de bayona
The beginning half of the Olvidado
The beginning of the Norte...

And you are a geologist or simply a rock afficionado, then...
Here is a paper you will love!:

https://www.researchgate.net/publication/291833095_Geologic_map_of_the_Basque-Cantabrian_Basin_and_a_new_tectonic_interpretation_of_the_Basque_Arc

It has two beautiful and detailed geological maps of the Basque-Cantabrian Basin that you can download.
Just wonderful!
(This whole area is geologically complicated, and immensely interesting - especially the coast along the start of the Norte between San Sebastian and Zumaia, which is an Unesco world geo-park, famous for the extensive exposures of many eons of strata at low tide.)