We have been to Paris a few times, and no longer need to see the standard first time sights. But, flying standby, we may get 'stuck' there at CDG for a day or two, and need suggestions for how to see something new or stay occupied, ( we have never been to the Aeroville shopping center, so that's one possiblity to keep from getting airport boredom).
Any suggestions for expeditions we can readily take from CDG, either overnight or a 1/2 day trip that would allow us to still get back to CDG by 2 in the afternoon?