Hundreds of gown- and tuxedo-clad partygoers, including Naomi Campbell and Donald Trump Jr., filtered into 7 World Trade Center Friday evening for a dinner and fashion show benefiting the charity Operation Smile. The guests made their way to the 52nd floor, which was painted black and adorned with large color photographs and gray floor-to-ceiling draperies for the occasion.

While the Grand Ballroom at the Plaza Hotel is closed for renovations, the top floors of 7 World Trade Center — a glass office tower rebuilt and reopened less than five years after the September 11, 2001, terrorist attacks reduced the original tower to rubble — are emerging as see-and-be-seen venues for fashion shows, charity lunches, and black-tie galas. The building’s chameleonlike spaces have been transformed into a Miami Beach-style nightclub with clusters of sleek, white couches and light installations for a Calvin Klein fashion show afterparty last fall, and into an urban garden filled with 5,000 red and pink roses for a Valentino fragrance launch in November. Tonight, an ornate runway will wrap around the 50th floor, custom-built for the Christian Dior Resort Fashion Show.

The editor of the event-planning magazine BiZBash, Chad Kaydo, has called 7 World Trade “the space of the year.” A full floor there — the top three are the most often used for parties — rents for $25,000 a day, though Silverstein Properties, which owns the tower, has occasionally donated a space to schools and community groups to use for a meeting or a benefit. A fashion house, charity, corporation or school renting — or borrowing — the space is responsible for expenses such as food, beverages, lighting, music, and décor.

“This is a blank canvas, and you can just cater it to whatever you want to do,” the events manager for 7 World Trade Center, Rebecca Shalomoff, said. “People say, all the time, ‘No one will ever be able to copy us.'”

Regardless of how the raw, airy spaces are dressed, their biggest draw, many say, is their sweeping 360-degree views of New York City and its surroundings.

The “mesmerizing” views were one of the things that pulled the spiritual leader of the SoHo Synagogue, Rabbi Dovi Scheiner, to the top-floor space, where the synagogue held its June 2006 fund-raising gala, which was attended by about 950 mostly young people. The venue’s significance “in terms of the rebirth of downtown, which is what the SoHo Synagogue is all about” was another, Rabbi Scheiner said.

The rabbi, whose synagogue held its benefit at 7 World Trade Center just weeks after the tower reopened, said he was also attracted to the novelty of locale. “So many venues, they’re beautiful spaces, but they’re overused — everyone already has so many memories associated with them,” Rabbi Scheiner said. “We wanted to set the trend instead.”

The SoHo Synagogue’s fund-raiser was a sold-out success, but observers say the event that turned 7 World Trade into a brand-name party space was Calvin Klein’s Fashion Week event three months later. That party brought out the likes of actresses Lindsay Lohan, Drew Barrymore, and Maggie Gyllenhaal — and was fodder for the tabloid’s gossip columns.

A guest surveying the decked-out room, and the panoramic city views at last weekend’s Operation Sunshine gala, Sebastian Vargas, 28, said of the space: “It’s about glamour; it’s about good drinks, and a good time; it’s everything that you wish.”

Another guest, Edward Boyanoski, 21, marveled that he hadn’t seen such spectacular views since he visited the observation deck of the original World Trade Center towers about a decade ago.

Silverstein Properties never planned for the tower’s top floors to be party spaces, according to a spokesman, Dara McQuillan. The company originally had rented out or donated empty floors “as a way to get a lot of people into the building and show it off to a lot of people who hadn’t been to the World Trade Center site for a while,” he said.

Even though Silverstein did not advertise its yet-to-be-leased floors as meeting and gala spaces, the venue became a word-of-mouth sensation. By earlier this year, the company was fielding scores of inquiries from organizations interested in renting out gathering space.

Despite the venue’s growing popularity, the company contends 7 World Trade Center’s days as a party spot are numbered. Today, the building is about 70% occupied. The remaining floors could be leased out by the end of the year, Mr. McQuillan said, forcing party planners to look elsewhere. “Part of the attraction — aside from the phenomenal views — is that, sooner or later, it will be office space, and that will be the end of that,” he said.

At least through the summer, though, the venue will be abuzz with parties celebrating schools, chefs, even Veuve Clicquot Champagne.
And after that?

“We’re waiting for our first event at the Freedom Tower,” Rabbi Scheiner said, referring to the centerpiece skyscraper planned for the World Trade Center site. “There will be a lot of places to party.”