Are there any private all-boys[1] schools that embrace this side of childhood? Look at tiger cubs and what not: they play, they bounce around, they fight, they figure out the world around them through investigation and exploration. I spent so much of my time outside as a kid, but I also spent a lot of time inside on the computer. Both were amazing worlds where your imagination could run wild; especially in the early…
I don't know about schools, but the kindergarten that I went to was a "nature"-kindergarten, where we were out in the forest 80% of the day, no matter if it rained or snowed. I must have catched a whole forest of insects, and investigated them. It is very popular in Denmark, and I love the forest and the outdoor because of it, especially the different seasons and their impact on nature.
Edit: that wikipedia article is maybe the worst thing ever. Learning to be comfortable in a natural environment, more free-form play, these are good things in an of themselves. I don't understand why people need to fall back on crackpot theories to justify a program like this.