Kids may play on equipment for a short time, he says, "but then they want to run around. They want to climb a hill, scramble over rocks, listen to the wind and play in the rain. They want to explore and discover rather than have their play experience defined by a piece of equipment."
So when his company, the Concord, N.H.-based Natural Playgrounds, builds a playground for a school or community, he tries to incorporate any equipment into the existing landscape, using or adding boulders, wooden beams, hammocks, water pumps or sand. Polycarbonate slides are built into embankments so the slides can be higher but the falls aren't as dangerous. They're also treated so that static electricity doesn't interfere with cochlear implants, and they're heat-resistant.
He might put in a water pump that needs to be primed, and sand that can be sculpted. Cedar, steel and copper can be turned into drums, musical fences, and tubular contraptions that make interesting sounds when gravel, water, sticks or hands come in contact with them. There are places to play quiet games, and also room to run with the gang.
Having the opportunity to do both is optimal, says Susan Solomon, author of "American Playgrounds" and the upcoming "The Science of Play" (both from University Press of New England). The trend toward more natural playgrounds, she says, is due partly to the high cost of the prefabricated, themed structures (jungle, pirate ship, tiny town) found in so many playgrounds today. It's also the result of growing interest in nature and local products, and of parental nostalgia for what is remembered as a more unfettered childhood.
Playgrounds in recent years — including some natural playgrounds — have gotten a little tame, Solomon says. Safety and liability concerns have driven out many tall or fast pieces of equipment.
And with them some of the fun. "They don't allow kids to take chances," Solomon says.
"Risk involves uncertain outcomes — going fast, reaching great heights or even hiding, in order to overcome primal fears and create exhilaration."
Restoring some of that excitement safely is one goal of designers of natural playgrounds.
The Woodland Discovery Playground at Shelby Farms Park in Memphis, Tenn., is a 3.5-acre amalgam of nature, naturalistic elements, and steel and plastic structures. It was developed by the New York-based design firm James Corner Field Operations after a series of workshops with local kids.
"What was so remarkable was that most children actually preferred woodland exploration to playing on the existing playground that occupied the site," says the firm's senior designer, Sarah Weidner Astheimer.
The resulting playground consists of six play "nests"; features include climbing walls, a bright red suspended net, a variety of swings, tree forts, vines and a place for quiet play.
A mix of natural and manmade challenges is also the recipe recommended by Paige Johnson, who writes a blog called Playground Designs. A few natural rocks and tree stumps aren't enough, she says.
"Some advocates even reject swings or slides, but the experience of dynamic motion, where a child feels a temporary loss of body control, is part of great play," she says. "It makes even grownups laugh."
A natural playground needs a few key elements, according to Johnson: a hill, boulders and stumps to climb on; rocks and gravel to dig in; paths and perhaps a little bridge to traverse; and a gate or door that kids can turn into a portal of their own. Finally, there should be a pile of loose parts: wood blocks, bricks or boxes of donated junk that can be turned into an imaginative, free-wheeling experience.