When I was a kid, the neighborhood boys built a tree house in an old cottonwood that stood in an empty lot down the street.  The stairs were short lengths of 2x4s nailed to the tree trunk.  From the ground the tree house didn’t look like much, a crude structure of scrap plywood constructed in the way 12-year-old boys with no carpentry experience would build it.  I never saw the inside because girls weren’t allowed. Read more