Imagination Playground at Burling Slip, New York, New York.In 1888, the psychologist Stanley Hall published a story about a sand pile. A minor classic, it describes how a group of children created a world out of a single load of sand. These children were diligent, they were imaginative, they were remarkably adult.

More than a century later, at the architect David Rockwell’s Imagination Playground in lower Manhattan, small humans scurry back and forth all day long, carrying Rockwell’s oversized blue foam blocks from self-devised task to self-devised task. These children are intent, they are cooperative, they are resourceful. The scene resembles nothing so much as Stanley Hall’s sand pile—with each grain of sand much bigger and much bluer. (Except for the bits of actual sand, that is.)

More than any playground in recent memory, the Imagination Playground has inspired an outburst of excitement. It’s a hit with the hip parents who take their kids to Dan Zanes concerts, and is just as crowded as one. But it also represents something much more mundane: the triumph of loose parts. After a century of creating playgrounds for children, of drilling swing sets and plastic forts into the ground, we have come back to children creating their own playgrounds. Loose parts—sand, water, blocks—are having a moment.

The resurgence of loose parts is an attempt to put the play back in playgrounds. The late 1960s and early 1970s were a time of exuberant playground design, culminating in the great Richard Dattner adventure playgrounds in New York City. Then the grownups got skittish. Down came the merry-go-rounds and the jungle gyms, and in their place, a landscape of legally-insulated, brightly-colored, spongy-floored, hard-plastic structures took root. Today, walking onto a children’s playground is like exiting the interstate: Regardless of where you are, you see the exact same thing.

A lot of people agree that playgrounds are now too boring, and for years there’s been talk about how we should make them more challenging, more risky. But so far, that talk hasn’t turned into more interesting playgrounds. The most adventurous playgrounds tend to be singular projects, often built through fundraising, for the rich. (A genuine exception is this amazing project in Philadelphia.) “People talk about making playgrounds more risky,” says Susan Solomon, the author of American Playgrounds, which charts their demise. “But there’s this sense that if you talk about it, that’s enough. There’s this very real reluctance to get involved in anything that might at least potentially cause an injury.”

In Europe, the assumptions are radically different. Even the head of play safety at England’s Royal Society for the Prevention of Accidents—a man whom you’d assume would be paranoid about preventing all accidents—has said that “children should be exposed to a certain degree of risk, not because an activity is risky per se but because it is fun, exciting, and challenging.”

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