I'm Spanish but I live in Asturias, in the north of the country. Not many tourists come, it's more likely to meet travellers. This area is absolutely different to the rest of Spain, high mountains, inmense sandy beaches and green fields everywhere. It's a little bit like the north of England or Scotland.
I would also like to recommend you Caceres. The city is a monument, the old city is full of palaces, churches, etc, no cars and not many tourists. The villages around it are really lovely, food is great but if you during August, it's really really hot. You can't walk at midday because you melt. Not many people visit it but it's worth doing it.
Greetings from Spain
Obaya