spain first timers

hi all, wondered if anyone could suggest a good area/campsite to stay for about 3 weeks in june next year,we have not been to spain with our van before and only want to travel about 3hours at the most from santander, can anyone help,we hope to use acsi and or camping cheques, we have looked at loads of sites but as we dont know the areas are looking for personal reccomendations, quiet with villages near by and good walking are what we like, any alan wickers out there???? THANKS AND  ENJOY THE WEATHER!!!! WHILST IT LASTS, jean