
There are several public pools scattered around Paris - but most of them are single pools with limited hours that are usually quite crowded. But smack in the middle of Montparnasse you will find the best swimming experience to be had in the city of light - Piscine Armand Massard, 66 Boulevard du Montparnasse (tel. 01 45 38 65 19).
Admission is just €3 - open to the public daily. Check for times:
http://ville.france.free.fr/horaires_piscines/ARMAND_MASSARD.php

This facility is a delight. First of all - it's not just one pool, but two large pools - and one smaller shallow pool perfect for children or water isometrics.
With two large pools available there is room enough for areas devoted to both lap swimming and free-style. And the pools are heated just right to make for a quite enjoyable dip.
The dressing area is for both men and women, and is equipped with private changing rooms. The lockers are large enough for all your clothes and a backpack (not the case at other Paris pools) and each has an electronic combination (like a hotel safe) so you needn't bring a padlock. And the entire area is kept spotless.

Wall mounted hair dryers are also provided free of charge.
So if you're feeling the need for an energizing exercise experience - at a very reasonable price - head over toMontparnasse for one of the best swimming experiences you'll find anywhere.