I ran across an interesting article on El País, Spain's national newspaper, that reminded me of a forum question I saw a couple of weeks ago inquiring about where the upper/lower class citizens live in Spain.
Well I think this article can answer your question, I've linked the English-language version: https://elpais.com/elpais/2019/01/18/inenglish/1547810069_248100.html
The article looks at statistics of Spain’s richest and poorest areas based on 2016 figures from AEAT (Spain's tax agency). One can even search for specific neighborhoods based on the postcode. For example 08012 is for Vila de Gràcia, a popular "hip" neighborhood in Barcelona. Now compare that with the postcode for the equally hip Sacromonte-Albaicín neighborhood in Granada, 18010.
A little geographic data-science for your Friday ;)