Backyard Playgrounds : Build Amazing Treehouses, Ninja Projects, Obstacle Courses, and More!, Paperback by Stiles, David; Stiles, Jeanie, ISBN 1510763287, ISBN-13 9781510763289, Like New Used, Free shipping in the US

"Authors Jean and David Stiles offer user-friendly plans (all hand-drawn by David) and step-by-step instructions to help you build something great in your own backyard. They offer a range of easy, timeless projects that can be made in an afternoon--trolley ride, treasure chest, circle swing, lemonade stand--alongside more ambitious projects, like the warped wall and treehouse"--