Depending on the length of your stay I would suggest taking the train (runs right through the whole area) to Barcelona. Great for museums, art galleries, shopping and people watching. The train prices are very reasonable and the journey is verymanageable in a day. Also try going north to Girona (visit the old quarters) or Figueras for the Dali museum and the best ever hot chocolate! The trains really are good and you get scenic views of the sea and coast as well.
We have been persuaded to join paternal grandparents and DP's brother and sister (aged 10 and 13) on an all inclusive holiday at Easter. This is their usual style of holiday but not ours and I suspect they will want to just stay in the resort all week to enjoy the evening entertainment etc. Yes I am trying really hard not to sound like a snob here and yes they do already think I am one. DD who is 5 will adore it but I think DP and I will need to escape a few times in order to last the week. Does anyone have any suggestions?