The Piscine Josephine Baker, the floating pool on the Seine at the foot of the Bibliothèque Nationale, just reopened for the season through September 4. You can swim, take aquagym classes, or just sunbathe on the vast wooden deck and watch the boats chug by on the river.

10am-10pm Monday, Wednesday and Thursday, 10am-midnight on Tuesday and Friday, and 10am-8pm Saturday-Sunday. Aquagym classes daily 9am-10am. Entry is €5 for adults, €2.60 for kids. Don’t forget your speedos, boys (no shorts allowed in the pool).