NYC Parks/Malcolm Pinckney

Summer is another country, its flag a rectangle of chlorinated turquiose, its anthem a lifeguard's piercing whistle, its essential right the pursuit of happiness. Its border crossing is a semicircular arch of ancient-seeming Roman brick, worthy of Sullivan or Lutyens, in the middle of scrappy McCarren Park between Greenpoint and Williamsburg in Brooklyn, New York. For years, since 1984, that crossing was closed, the victim of recession and a venue for the strife of vice and violence. In 2005, however, with the advent of a hipster-heaven concert series that featured the likes of the Beastie Boys and Wilco in McCarren Park Pool’s vast dry basin, Summer could be visited again for just a few nights a year.

And now, with the late June opening day of outdoor public swimming pools across New York—and especially of the McCarren Park Pool, following a three-year, $50 million rehabilitation by Rogers Marvel Architects—Summer's borders are open again. The pool and its monumental pavilions date to 1936, the work of Mayor Fiorello La Guardia, Parks Commissioner Robert Moses, and the underappreciated in-house architect Aymar Embury II, who gave the complex a dapper dignity in heavy masonry and airy plaster. The refurbishment (the first of eight major park rehabilitation projects scheduled for between now and 2030 in the city's PlaNYC plan) arrays a community room, computer lab, weight room, and basketball court inside existing structures. There are new changing pavilions on either side of that great arch—the graceful tapering profile of their roof canopies closely echoing that of the clerestory above Embury's gateway. Within the changing rooms, skylights, and playfully curved fins focus and diffuse light, which is already on a glittering bounce from the nearby water's surface—adding a luminous grace to what could easily have been a utilitarian space.

Throughout, there's an adaptive reuse of places and materials, the kind of thoughtful weaving of surface and space in which Rogers Marvel specializes. Hundreds of old baskets from the pool's original locker rooms have been ingeniously repurposed as ceiling panels, while many interiors are clad in hardwood boards salvaged from demolished portions of another Summer border crossing, the Coney Island Boardwalk. McCarren Pool itself has been purposefully modified. While the original featured four Olympic size–pools’ worth of water in one big quadrangle, the renovation introduces a rectangular peninsula (which will become a skating rink in winter) between the two new changing pavilions. The new layout organizes the now 38,000-square-foot, C-shaped pool into three areas: a gently-sloping beach-like zone for tots, an 82-foot-wide zone for lanes and laps, and the remainder for the general meditation and mayhem of a summertime swim.

At 3:00 p.m. on opening day, dozens of lifeguard whistles rang out across the big blue field of water, announcing an everybody-out-of-the-pool shift change above the joyful noise of boisterous New Yorkers of every shape and color. The sound was as thrilling as a plunge into cold water on a hot day. And for as long as it lasted, you could believe that Summer was not just a promised land from which we are exiled every year, but somewhere to live forever.