Although it isn’t somewhere at all recommendable as place to stay as a base from which to visit Tokyo, I do HIGHLY recommend the “Tove Jansson Akebono Children's Forest Park” as a place for a long visit with young children.

Take a picnic and give the kids plenty of time to let them explore. We have truly magical memories of this very special park.

Another place that is wonderful for small children (and just as absorbing for parents also) is the Koto City Fukugawa Edo Museum near Kiyosumi-Shirakawa Station. Again, not a recommendation for a base, although I’d personally prefer being here than Odaiba, I like the neighbourhood, Kiyosumi Gardens is a delight and the next door park has decent playground facilities.