Travel advice 

Hi AL
I hope you don't think I'm being cheeky but I would appreciate your advice. My wife and I are currently in southern France and will shortly be heading off in our campervan to visit northern Spain, hoping to get to the far north-west. On checking our time schedule, we find that we have a week extra, so are thinking of visiting northern Portugal, although we are unlikely to get further south than Porto. As we have no travel guides to Portugal, can you recommend any places to visit. 
Thanks for any advice. 
Best wishes