Spain Square, Seville
I had the privilege of being in Sevilla for Holy Week. The floats were immense and you could feel the pride in being one of the carriers (I don’t remember the name). Apparently these individuals spend months prepping to be strong enough for the duty. The locals take Holy Week very seriously, dressing to the nines to stand in the street and worship with their families. Whenever a float turned the corner to become visible, a hush fell and it was complete silence, just enough to hear the feet of the carriers marching through.
language is more of an issue than in Barcelona or Madrid but you'll be able to get by almost anywhere - there's menus in English pretty much everywhere. The new food market by the river is amazing, next to Puente de Triana. And for football, there's always Betis too.!

Eryri is gorgeous. If you get the chance I'd also recommend Cadair Idris (Idris' Throne/Seat) which isn't too far away and has some brilliant wildlife and habitats.

Game of thrones filmed in many places of Sevilla also!