If you are staying at at 4+ star hotel at Barcelona most probably you have a pool there that you can enjoy. But if you’re not, there is a local secret that might come in handy. All around the city, there are partly-government-owned gyms where you can pay per visit. And of course, use their pools.
There are many to choose from. In the picture, you can see the recently opened gym at the Ciutadella park (check the Ciutadella park article). The wooden building blends beautifully with its environment and has a great open-air pool in the upper deck. it is open until 23:00 on weekdays, but the pool is closed half an hour before.
Also worth a visit is the Club Natació Atlètic, at the Barceloneta. It has more pools, one overlooking the sea and a special entrance to the beach, as well as a wellness area. It is located at the Plaça del Mar s/n.
The municipal pools are used for fitness swimming, but you can also chill out in the hot tubs and jacuzzis. Keep in mind that you can only buy a day-ticket if the gym is not over capacity at the moment. If so… just come back a little later.