In Pamela Druckerman’s “Bringing Up Bébé,” the playground forms a fertile backdrop for her pop-sociological observations about child-rearing, French vs. American style. The upper-middle-class Manhattan moms (she can tell by the price of their handbags) follow their kids around the gated toddler playground narrating their activities. The French moms sit on the edge of the sandbox and chat with other adults. The Brooklyn dads follow their children down the slide. The French moms sit on a bench and chat with other adults. Her theory, a bestselling one, is that French parenting consists of more non, more équilibre, and thus more time for adults to be adults.

It never occurs to her that maybe it is the playgrounds that encourage parents to act this way. Most New York playgrounds are designed for the protection of children: padded surfaces, equipment labelled by age appropriateness, and a ban on unaccompanied adults. Frankly, it is hard to see why an adult without a child would want to enter. There’s often little seating, minimal shade, and no place to set down a coffee except in a stroller cup holder. As for those parents who don’t want to helicopter, the perimeter benches can be far from where children play, sight lines blocked by the bulky climbing structures. Standard New York playgrounds are made for a single activity—child’s play—not family socializing or even adult enjoyment.

The planners of New York City’s Governors Island, an ice-cream-cone-shaped piece of land a half mile from the end of Manhattan, see play somewhat differently, and are designing their first thirty acres of park and public space accordingly. “People spend several hours here” on the weekends, says Leslie Koch, president of the Trust for Governors Island. Free ferries from Manhattan and Brooklyn bring visitors in for extended afternoons. “You wander through the island, you have an idea or you may not, the kids run around. There aren’t precedents for that kind of place. It’s different than a beach or an urban park, or even a state park, where you go to barbecue.” She adds, “Early on we said we didn’t want to have playgrounds, but we didn’t say what that meant.”

It was up to the Dutch landscape architects West 8, led by principal Adriaan Geuze, to create that meaning. “In park history, French and Italian parks had a wall or a fence, like Luxembourg, Tuileries,” Geuze says. “The idea was that you enter like a royal, your sorrow dropping off your shoulders. At Governors Island you arrive by ferry, and you really leave your life of sorrow and pain. That’s what the ferry does for you.”

Much of the northern end of the island is a historic district, with minimal design interventions. But once you pass through the tall arch of McKim Mead & White’s 1929 Liggett Hall, a former barracks, West 8’s biomorphic, layered landscape vision will dominate. In the original plan, Liggett Terrace was to have a reflecting pool, but after seeing the popularity of water play at Brooklyn Bridge Park and Battery Park, the architects decided the area should be the center of intergenerational activity, with three sections of mosaic pavement from which water sprays. “We wanted a water feature that could be playful for kids as well as adults, and then at night it is a spectacular feature to look at,” Geuze says. “It needed to function equally well whether or not the water was turned on.”

These fountains will be interspersed with café tables and labyrinthine hedges. The fountains are integrated into the pavement, so a meal and splashing can take place side by side. The hedges are intricate but low, so if you are sitting down at a table with a coffee or fish tacos (there will be food trucks), you can still see the head of a three-year old. The sculpted edges of the planters double as benches, turning the whole six-acre terrace into a version of that mellow French sandbox.

“If you create a park-like environment and people feel really free, adults hang out and participate like children do,” Geuze says. Contrast the concept for Liggett Terrace with the experience at Pier 6 at Brooklyn Bridge Park, an access point for the ferry to Governors Island. To date, Pier 6 consists of four landscaped, gated playgrounds, one with swings, one with water, one with sand, and one for climbing. There’s a separate beach-volleyball court, and a separate park building with food. If you aren’t pushing your kid on the swing, narrating every to and fro, the only place to sit is the springy rubber ground.

In the six summers that Governors Island has been open to the public, the Trust has had ample time to experiment and observe what people do differently on an island. A set of swings for adults at the southern end went unused for weeks. “People would stop their bicycles in front of them and look to their left and right,” Koch says. “They didn’t believe they were permitted to swing.” But a few grownups broke the ice, and the swings have become a popular stopping-off place. Meanwhile, getting one of the nearby hammocks—an idea inspired by an offhand comment by illustrator Maira Kalman that it should become “the island of a thousand hammocks”—has became a competitive enterprise.