The Tuileries contain a small playground with a carousel and pony rides. Every summer there is a carnival with rides, games, etc. set up in the gardens. This generally includes an immense ferris wheel with views out over the entire city from the top. Near the Concorde end there is a pond where children sail their small boats. All in all, it is a perfect spot for unwinding from the immensity of the Louvre. See more at Family Travel Forum: http://bit.ly/as8tNY
Another beautifully landscaped garden in Paris, right next to the Louvre. In the summer, there is a carnival set up with a ferris wheel (it's expensive, but offers an amazing view of Paris) and some great rides for kids.
When we're in the center of town, shopping, eating or museum hopping, this is a great park to hit up and burn off some energy. The carrousel and in-ground trampolines are Charles' favorites. See more at Tot 'n Tow: http://bit.ly/9Zonli