I'm taking my 16 year old niece to Paris for a few days with my 2 DS' they are 4 years and 11 months. Will take my niece to all the sights etc but I think my boys might need to let off steam esp the 11month old who has just started walking and won't want to be stuck in the pushchair all day. Has anyone got any good ideas for places the boys can run around either within museums, in softplay centers or just anywhere they can roam freely. We won't have a car so will need to be walking or metro ride from the center.