The author tells of his work around the country and world on transforming how schools do recess, free play, and outside time by transforming their outdoor spaces to match. Instead of a playground of fixed structures like traditional school grounds, newer spaces are filled with loose materials that children can use to build forts, dens, and tree houses, complete with running water, sand play areas, and fire pits for cooking. Creating optimum play and learning opportunities requires three elements: time, space, and materials. One example of this is the Hands-on-Nature Anarchy Zone at Ithaca Children's Garden in Ithaca, N.Y. It is one of the leading examples of a child-structured, play-based environment.