New York City, with its rich history of public playgrounds, is on the verge of a bold experiment in the way children play, one that could accelerate the trend away from monkey bars, swings and seesaws used by generations of city children.

In an unusual public-private partnership, the city is developing a playground near the South Street Seaport that will have trained “play workers” on hand to help children interact with features of the new playground: water, ramps, sand and specially designed objects meant to spur the imagination.