I usually mention that #Spain is just a puzzle of cultures that (push to) exist by themselves, and then may appear the #separatist sentiment.
Today an interesting map (apparently) from 2020 just crossed paths with me, and I intend to keep it at hand for these occasions that I'd like to bring the #multiculturality that actually builds this country.
For the attribution of the image, I just can relate that I took it from this Mastodon toot, pointing to this post at Maps on the Web (avoid, too many ads), that points to a Reddit thread (the image was removed).