We are free to spend as much time outdoors as we want, enjoying the natural world around us.
I'm sure girls appreciate this too, but boys NEED it. They do better with periodic breaks for fresh air and large-muscle activity. Even Wyatt, my oldest, needs it. And high schools don't exactly have recess, y'know? He'll frequently take a break and go bounce on the trampoline, or go for a fifteen minute bike ride. Or I'll send all the boys outside to do laps (at least as many laps around the house as you are old and don't come back until you're sweaty).
But aside from releasing their boundless energy, we love getting out of the house and into God's creation. We watch fish in the creek, see the eagles bringing food to the nest, count the baby ducks in the pond, and watch the lilies gradually taking over the swamp. That's a lot better than looking at pictures of ducks and fish and eagles in a book.