The concept is simple- three floors of a Victorian mansion filled with books and toys where kids enjoy unstructured play- but it is an absolute winner. My (almost) 3 year old thought this was the greatest place he'd ever seen and didn't want to ever leave. The outdoor playground was incredible too. If you have kids, this is one of the must-see attractions in the Northeast. The mansion itself would probably appeal to kids up to 5, while the playground would be enjoyed by kids up to 12 or so, as it has swings and enormous rope-climbing contraption.