They were designed for the 1964 World’s Fair as sleek, space-age visions of the future: three towers topped by flying-saucer-like platforms, and a pavilion of pillars with a suspended, shimmering roof that was billed as the “Tent of Tomorrow.”

That imagined tomorrow has come and gone. Now the structures are abandoned relics, with rusted beams, faded paint and cracked concrete.

As the fair’s 50th anniversary approaches, the remains of the New York State Pavilion are getting renewed attention, from preservationists who believe they should be restored, and from critics who see them as hulking eyesores that should be torn down. Neither option would come cheap: an estimated $14 million for demolition and $32 million to $72 million for renovation.

“It is the Eiffel Tower of Queens,” says Matthew Silva, who’s making a documentary about the pavilion in Queens’ Flushing Meadows Corona Park, comparing it to a remnant of the 1889 Paris Exposition that was also threatened with demolition before it was saved.

Designed by famed architect Philip Johnson, the New York structures debuted with the rest of the World’s Fair on April 22, 1964, and quickly became among its most popular attractions.

Visitors rode glass “Sky Streak” elevators to the observation deck of a 226-foot tower — the highest point in the fair. The two shorter towers, at 150 and 60 feet, held a cafeteria and a VIP lounge.

The pavilion’s 16, 100-foot-tall concrete columns supported what was then the largest suspended roof in the world, a 50,000 square-foot expanse of translucent, multicolored tiles. On the floor below was a $1 million, 9,000-square-foot terrazzo tile map of the state, with details of cities, towns and highways.

In the years after the fair, the pavilion was used as a music venue. In the ’70s, it became a roller skating rink until the collapse of the ceiling tiles, leaving only bare cables behind.

The towers, while still structurally sound, were abandoned as observation decks long ago for safety reasons. Their retro-futuristic look has been most widely known from its use in movies.

Although occasionally opened for tours, the towers and pavilion — the last major structures still standing from the World’s Fair that have not been preserved — have largely served as a stoic landmark for travelers on the Van Wyck Expressway. Two pad-locked gates — one chain-link, one metal — keep the Tent of Tomorrow shuttered.

“It should be called the ‘Tent of Yesterday,'” says Ben Haber, who lives near the park. “This is not the Parthenon, it’s not the Sphinx, it’s not the pyramids. … So what’s so special that we should keep it?”

At the heart of the debate is the cost. While the city’s Parks Department commissioned studies on the cost of scrapping or renovating the complex, it is still unclear where that money would come from and, if restored, how the structures would be used. If the money comes through, work on the city-owned pavilion could begin as early as next year once officials make a decision.

Queens Borough President Melinda Katz has formed a task force dedicated to preserving the pavilion, noting that other structures from the World’s Fair have been saved, most notably the 12-story-tall metal globe called the Unisphere, the Hall of Science and the Queens Museum.

Among the ideas are to convert the towers once again into observation decks or an elevated garden or even a platform for bungee jumping, with the open-air pavilion turned into a performance space with a removable stage and bleachers.

While that debate plays out, a small group of World’s Fair buffs has formed to repaint the pavilion so it can be open to the public briefly for an April 22 anniversary event. The towers will still be off limits.

“I just loved this pavilion,” says 63-year-old volunteer painter John Piro. “And as the years went on I saw it decay and it just like tore my heart.”

Haber, the Queens resident, argues that nostalgia is fine, but the cost of saving the complex is just too much.

“Urban parks are the backyards for people who don’t have them — so they can sit on the grass, look at trees, flowers, water,” Haber says. “They do not want to look at glass, steel and cement structures.”

(AP)