Barcelona pools -- www.barcelona-culture.com/swimming.html. You can probably swim at the Olympic pool. It's most likely open to the public. Last year in Sydney I swam at the Olympic pool there.
But...if you do nothing else in Barcelona...at least enjoy the Ramblas (en.m.wikipedia.org/.../La_Rambla,_Barcelona). Especially on the weekends when the sidewalk pastel artists come out. Probably ought to check out the the cathedral Sagrada Familia too. You won't regret doing either/both. THEN...go for your swim. Barcelona is a great city don't miss out on the awesome cultural attractions. Have fun!!!
Dan
