Paris is kind of partially swimmable in the Summer: a little portion of the Canal Saint-Martin is open to bathing under supervision during the months of July an

Paris is kind of partially swimmable in the Summer: a little portion of the Canal Saint-Martin is open to bathing under supervision during the months of July and August, only during weekends. This is because otherwise the canal is a dangerous place to bath because of the locks. The city plans to open the Seine to bathing by 2025, as well a small lake in the Bois de Vincennes. Things move slowly, but in a good direction.