Barcelona is the Spanish city you probably hear the most about but I’ll make the case here why you should go to Valencia instead.
First of all, Valencia is such a better value…
I spent about three weeks in Barcelona and Valencia seems to have everything that Barcelona does at about half to a third of the cost. In Barcelona, a very simple flatshare in a kind of cool neighborhood costs 31 Euros a night, and a shitty hostel costs $22 a night whereas in Valencia I found that not awful private room flatshares via AirBNB cost $10-$15.
In general, the wifi in Barcelona is quite mediocre, the speed and reliability are so wanting that it negatively affected my productivity during the time I spent there. Disappointingly, there’s just a single real digital nomad-friendly cafe in Barcelona. In contrast, the wifi in Valencia is muy buen! At cafes, restaurants, hostels, and Airbnb apartments I consistently found the +20MB up/down connection that I need to do work.
If you want to go shopping at a Prada store, Barcelona’s the city for you but Valencia is overall a whole lot better value for nomadic seducers.