Not too many have pools, but I have stayed at one called the gran havana, that does have a small rooftop pool and sun terrace with loungers. Its a short walk (about 5 mins) from the top of Las Ramblas and Catalunya square and is a modern well appointed hotel (with lots of twin rooms). When we went, they had a 3 night for the price of two deal on through their website. It has a lot of Americans staying one night, before a cruise departure (as do a lot of hotels) so the bar is small but they do speak good English. If you go in August, you must go the the Gracia Fiesta as part of your hen night, its an amazing street party....