Saw this great article from the BBC today covering the little known region of Val d'Aran in northern Catalonia, and their unique language Aranese. Spain is a melting pot of a number of different languages, but while most probably know about Basque or Catalan, Aranese (a relative of Gascon and distinct from Catalan) I don't think is well known outside of Spain, so I was quite surprised when I saw the BBC had covered it lol!
Here's the link: https://www.bbc.com/travel/article/20220117-aranese-spains-little-known-language
From the traveler's perspective, I feel that the Val d'Aran could offer an interesting alternative mountain escape to the Alps or the Picos de Europa, that remains largely undiscovered by foreigners I think. The capital of the region, Vielha, makes for a great base to explore the region, which is also well known in Spain for its great skiing.
Hope this article can inspire some of those who are on the hunt for "backdoors" even in a very touristy country like Spain :)