Vancouver: Can't say enough about Stanley Park one of the best parks I've ever been too with my son, who is now 7. We also travel extensively and are always looking for a little oasis for our son to burn off some energy. The aquarium is great and you can still watch the white Beluga whale show from an outside viewing area without paying the aquarium admission fee if you are just going to be there for a short time.

Paris: Luxembourg Gardens has a really fun playground with lots of equipment there is a small admission fee. They also have the nicest pony rides I've ever seen for kids. The ponies are tethered side by side (instead of one behind the other) and they are led down a beautiful tree lined path. From a distance the kids look like little cowboys off in the distance.

New York: The Ancient Playground which is right next to the Metropolitan Museum of Art in Central Park. The boat pond (from Stewart Little) is also a lot of fun for the kids. I also like the lawn and grounds of Columbia University at 116th Street and Broadway. There is no play equipment but it is a huge open area without any cars. The Bronx Zoo is also fabulous.