During the summer of 1936, master builder Robert Moses and Mayor La Guardia opened 11 city “play centers,” comprising swimming pools and surrounding recreational facilities. Several of these now possess landmark status, including Williamsburg’s McCarren Play Center, which was designated a city landmark last week by the Landmarks Preservation Commission.

This classification is a further testimony to the rise of the Moses’ reputation in the years since Robert Caro’s Pulitzer Prize-winning biography of the builder, “The Power Broker,” was published in 1974. At that time, few could have conceived that, decades hence, preservationists would seek to save so much of the Moses legacy.

As the play centers go, McCarren ranks high in interest, both because of its unique — and tragic — history, and because it’s now smack in the center of one of the city’s hottest development zones for luxury housing. All the Moses play centers bear distinctive designs, and some may be handsomer than McCarren. But McCarren’s monumental aspect may surpass the others, fittingly, for its capacity exceeded any of them. At one time, its pools (a large main pool and flanking wading and diving pools) could accommodate 6,880 swimmers. The play center’s massive arches loom over surrounding McCarren Park and Williamsburg streets like the ancient ruins of a once-mighty civilization.

New York City’s Department of Parks & Recreation closed the play center in 1983 to refurbish it for its 50th anniversary in 1986. Back in 1983, however, this part of Williamsburg, while it had begun to attract artists, had not yet attained hipster haven status, let alone attract the interest of developers of luxury residences.

Williamsburg had suffered from factory closings, population exodus, and rising crime. On one side of McCarren Park an Italian community — centered on Our Lady of Mount Carmel Church, where the annual dancing of the Giglio originates — hung on, while on the other side a Polish community didn’t just hang on, it grew.

These inner-city, working-class communities — desperately besieged, and officially ignored, during New York’s era of nightmarish crime — felt the play center to be a magnet for “undesirable elements.” Local pressure consequently led to the play center not reopening.

Over the years, some have tried, but none have succeeded, in bringing back the play center. In 1994, community activist Phyllis Yampolsky and others formed the McCarren Park Conservancy, but their plan to rehabilitate the facilities fell victim to shifting budget priorities after the terrorist attacks on September 11, 2001.

But now, it probably won’t be long before the play center is back in full swim. In the last couple of years, it has hosted, if not swimmers, then concerts and other events, such that it has become a hub of neighborhood activity — not just a visual landmark. The parks department has plans to refurbish the play center and reopen the pool, and this time no one objects. That’s a measure of how much Williamsburg has changed since 1983 — a microcosm, perhaps, of how much New York City has changed.

These days, it’s Williamsburg’s waterfront section that rivets most people’s attention as Toll Brothers’ Northside Piers rises glassily into the sky, soon to be followed by many other residential skyscrapers. Development has proceeded more rapidly along Williamsburg’s other coast — Bayard Street along the south side of the 36-acre park. The real estate Web log Curbed dubbed Bayard Street “Karl Fischer Row,” after the architect of four of the new luxury apartment buildings that have risen along that street in the last year or so: the 17-story 20 Bayard, 30 Bayard (“Aurora”), 50 Bayard (“Ikon”), and 64 Bayard. The Montreal-based Fischer firm opened a New York office in 1999, and has since established itself as a leading designer of apartment buildings in the current boom in Brooklyn, Manhattan, and Queens — not least in Williamsburg, where Karl Fischer designed the $90 million Schaefer Landing project that opened in 2005, as well as several other buildings.

Williamsburg’s new buildings tend to be glass-and-masonry buildings of the currently popular type, inspired in part by early 20th-century reinforced-concrete industrial buildings that are abundant in Williamsburg.

The play center stands near the northeast corner of Bayard and Lorimer streets. The landmark designation and the super-gentrification of the McCarren Park neighborhood virtually guarantee the rehabilitation of the pool — as does Mayor Bloomberg’s allocating $50 million to fund the effort.

In 1983, when the city closed the play center, artists had already begun to discover Williamsburg. In 1994, when the McCarren Park Conservancy began, hipsters had invaded. And no one had heard of Fresh Direct refrigerators.