Now, my tree-climbing days long behind me, I often think about the lasting value of those early, deliciously idle days. I have come to appreciate the long view afforded by those treetops. The woods were my Ritalin. Nature calmed me, focused me, and yet excited my senses.

I do not trust technology. I mean, I don't think we're in any danger of kids, you know, doing without video games in the future, but I am saying that their lives are largely out of balance.

A natural environment is far more complex than any playing field.

This tree house became our galleon, our spaceship, our Fort Apache...Ours was a learning tree. Through it we learned to trust ourselves and our abilities.

Natural playgrounds may decrease bullying.

It takes time--loose, unstructured dreamtime-- to experience nature in a meaningful way. Unless parents are vigilant, such time becomes a scarce resource, not because we intend it to shrink, but because time is consumed by multiple, invisible forces; because our culture currently places so little value on natural play.

Research suggests that exposure to the natural world - including nearby nature in cities - helps improve human health, well-being, and intellectual capacity in ways that science is only recently beginning to understand.