Forget Fifth Avenue, West Broadway or Columbus Circle—57th Street is the new gold coast. (Emily Anne Epstein)

Michael Stern was walking to a meeting last summer when he saw the vacant site, barely wider than a townhouse, at 107 West 57th Street. On one side was the Steinway Building, an 87-year-old city landmark with an etched white limestone façade. On the other was a dowdy old SRO about to be gutted and transformed into the Quin Hotel, yet another boutique confection for the tourist masses.

Yet it was not the barren lot’s immediate neighbors that set Mr. Stern’s heart racing, but another edifice further down the block: Gary Barnett’s One57. The 1,005-foot, 90-story tower was only about halfway built at the time, but already it was on its way to taking the crown, on the skyline and in the record books, as the city’s tallest apartment building. Billionaires were already circling the units, which ranged from $5 million to $115 million.

Looking from Mr. Barnett’s site to the one in front of him, Mr. Stern knew he had to have it.

“Right now, there is nowhere else in the city like 57th Street, and it is only going to get better,” Mr. Stern told The Observer. “You’ve got so much on the horizon. You’ve got proximity to Central Park, you’ve got proximity to some of the world’s most premier shopping. I think it’s perceived to be the dead center, heartbeat of the city.”

Mr. Barnett is not alone in that belief, as a number of the city’s biggest builders have set their sights on the strip, positioning a boulevard that is equal parts grand (Bergdorf Goodman) and greasy (the Brooklyn Diner) to become New York’s new gold coast.

Barry Sternlicht, the creator of the W and Starwood hotel chains, had already planted his flag at 107 West 57th Street, having bought the vacant lot from another developer for $52 million in 2005. Last year, Mr. Stern bought into the property for $40 million, and together they’re now planning a shard of an apartment tower, all boutique luxury beauty, shooting up some 700 feet and 50 stories, but only 34 feet wide. With its pointy top, this might become the most expensive toothpick ever made.

Towers skinnier than runway models have begun to rise skyward all along this hiding-in-plain-sight strip. All seem to be in pursuit of the same thing: better views and bigger payouts. Already, at least a dozen billionaires are said to have bought into One57, where two of the units have sold for $95 million, the highest price ever paid for a home in the city, topping even the $88 million penthouse at the grand 15 Central Park West. These are untold heights in a city famous for them.

“I’ve taken to calling it the billionaires’ belt,” said author and 58th Street resident Michael Gross.

Always lacking the cachet of better-known crosstown boulevards, 57th Street is having a moment, thanks to a confluence of decades-old zoning and newfound global wealth. While City Hall has played almost no role in the development of 57th Street in the past few years, the Tiffany-tinted thoroughfare may soon stand as the singular symbol of the Bloomberg era. All it takes is an apartment—average price: $20 million.

A big part of the appeal, of course, is that all of these buildings are condos, which don’t tend to exclude residents based on pedigree, the way co-ops do. An ill-gotten oligopoly and half a dozen divorces? Who cares! Welcome to 57th Street.

In addition to 107 and 157 West 57th Street, there is 432 Park Avenue, rising on the old Drake Hotel site between 56th and 57th streets, which Harry Macklowe has controlled for years. It will usurp Mr. Barnett’s record, becoming New York’s tallest tower, bar none, at a height of 1,397 feet. (That’s ignoring 1 World Trade’s 400-foot spire, but you can’t live on a pole.) So far, Mr. Macklowe and CIM have pegged the most expensive units at 432 Park Avenue in the $80 million range.

Not to be outdone, the brash Mr. Barnett is poised to one-up those who have one-upped him. For some time now, he has been planning a tower at 225 West 57th Street, on the corner of Broadway and West 57th Street.

Early speculation had been that the building would reach 1,250 feet, but some reconfigurations and a few more air rights deals have now yielded Mr. Barnett a tower of 1,550 feet—set to reclaim the crown of city’s tallest tower by a good 151 feet. Mr. Barnett’s 88-story tower will have New York City’s first Nordstrom in its base, a sure sign that the luxury brands clustered around Fifth and Madison will continue to migrate west.

Further down, both on the boulevard and on the skyline, is the Durst Organization’s 625 West 57th Street, the one major new rental tower on the strip. Every design magazine from here to Dubai cannot stop talking about the 32-story pyramid, which looks like a giant paper airplane crossed with an aircraft carrier, designed by Danish wunderkind Bjarke Ingels.

Among the other smaller developments on the stretch are a new brooding hotel on the southern side of 57th Street, designed by the rough-edged industrial glam outfit Roman and Williams. Mr. Barnett also controls a 50-foot-wide parcel at 16 West 57th Street that he bought last year for $80 million. The site, off Fifth Avenue, had previously been marketed as a boutique shopping spot and 28-story hotel, but given Mr. Barnett’s keen ability to assemble air rights, something much taller seems possible.

And all the way over on the corner of Second Avenue, World Wide Group is preparing to break ground on a 57-story avant-garde behemoth with 270 high-end apartments, designed by Roger Duffy of SOM. Earlier renderings showed a faceted tower, like an uncut diamond, but a source explained that the newest plans “undulate.”

The length of 57th Street has encompassed the broad sweep of humanity, the high and low, the cultured and the crass, the chichi and the chintzy. Like so much of the city in the past 11 years, its rough edges are being demolished and reshaped, fashioned anew. Manhattan is starting to look as much like Dubai as New York, and is starting to feel like it, too.

For a few glorious decades more than 100 years ago, 57th Street was one of the city’s most sought-after addresses, the home of Manhattan’s first luxury apartment towers.

Up until the late 19th century, crowded tenement houses served as refuges for the masses, while patricians kept to their own townhomes. Only with the construction of buildings such as The Osborne at 57th and Seventh in 1885 were the well-to-do convinced to abandon their own private buildings. Then as now, it was amenities like doormen and sprawling layouts that made the move so attractive, the most important of all—as always—being the views, albeit only 10, 11, 12 stories above the low-slung hordes.

The Alwyn Court, Mr. Gross’s home, still stands at the corner of 58th Street and Sixth Avenue, a limestone grandee built in 1907 with etched sculptures running up and down its façade, every inch detailed by a mason’s hand. Then there are Cass Gilbert’s Rodin Studios, the Art Deco Parc Vendome apartments of the 1930s and the Ritz Tower at Park Avenue, the tallest residential building in the city when completed in 1927. And one of the saddest examples, at 57th and Ninth Avenue, the horribly dilapidated but still grand Windermere.

“In a lot of ways, the city’s craze for apartment living began here,” Ronda Wist, vice president of preservation at the Municipal Art Society, said during a recent walk along 57th Street. “The archetypes are all here.”

While the grand dames were soon eclipsed as the city continued its inexorable move northward, 57th Street still had other attractions to recommend it. It was an art hub long before there was Soho or Chelsea, owing to the Fuller Building, the Steinway Building, Carnegie Hall and The Art Student League, the former home of Georgia O’Keeffe, Alexander Calder and Ai Weiwei.

It has also long been home to some of the city’s most exclusive shops, starting with the arrival of Henri Bendel at 10 West 57th Street in 1913. The Louisiana milliner had left behind Ninth Street in the Village to cater to the emerging uptown set, and it was here that he would introduce them to the likes of Coco Chanel. Bergdorf Goodman followed in 1962, when it bought and demolished the old Cornelius Vanderbilt II mansion that had lorded over the northwestern corner of Fifth and 57th, taking up the entire block. Now, LVMH Row stretches the entire length of the block on the other side of the street, clear down to Madison.

“It may not be Fifth Avenue, but there’s a five in the address, and that’s all a lot of these buyers care about; for the foreigners, it’s all they even know,” said retail real estate maven Faith Hope Consolo. “It could be Fifth Avenue in the 60s or Fifth Avenue in the 20s, their friends back home aren’t gonna know. All they see is the postcard address. It’s the same with 57th Street. They know Bendel’s, and now they know One57. To these people, the address matters more than what’s outside the door.”

A big reason for this boom is that there are few other places in the city with the right mix of regulations and existing development to allow for these kinds of towers. There are no height or landmark restrictions in Midtown, unlike areas like Tribeca or the Upper East Side, making going higher that much easier. Plus 57th Street has the added advantage of being an extra-wide street, which allows for even taller buildings. And being just two blocks south of the park, it really is the perfect location for an ostentatious tower, or a dozen.

But more important even than the physical geography of the place is its psychogeography, particularly for Chinese and Russian buyers, said Yuval Greenblatt, a vice president at Douglas Elliman who has run the firm’s Midtown office for more than a decade.

“It’s the center of the city. They’re near shopping and all the hotels, the St. Regis, the Pierre, the Plaza; they’ve got the theaters, and the businesses are there,” he said. “Plus it’s close to the hedge funds at the Solow Building and GM and Seagrams. It already had this international feel, and now more than ever.”

But is there really a market for so many multimillion-dollar homes all bunched up together like this? “I think so,” said Jonathan Miller, the master appraiser. “So long as the market isn’t flooded, which it’s really not, and we only get one or two of these projects a year, we should be fine.”

“Remember,” he added, “these buildings are big, but so are the apartments, so there really aren’t that many of them.” One57 has 135 units (plus a Hyatt hotel on the bottom half) and 432 Park has 128, while 107 West 57th Street has all of 27 units planned, each one taking up at least an entire floor and more than half will be duplexes.

Meanwhile, demand is skyrocketing like these towers. Just as these new buildings are in a different class, so are the buyers. “Before, this was a small investment, little more than a hotel room,” Mr. Greenblatt explained. “Now, these are real homes, big homes, with the nicest finishes. These are the type of buyers who own homes all over the world, so that’s what they want.”

Mr. Greenblatt actually believes that there has been pent-up demand for these kinds of apartments for years that is only being worked out now, and that it should last for years, as global wealth continues to concentrate in the hands of the few and find its way into New York and other world capitals. As of this year’s Forbes list, there are 1,226 billionaires. And counting. Economic uncertainty only spurs on this kind of investment, too, according to Mr. Miller.

“If you’re looking out from your apartment on the 70th or 60th, even the 50th floor, you’ve got a certain perspective on the city,” Mr. Greenblatt said. “You’re looking out over one of the most powerful cities in the world, and you’re on top.”

In 2006, when Mr. Gross left the Village after 17 years to take up residence in Alwyn Court, it was, he told The Observer at the time, “Precisely the kind of neighborhood that the Village used to be. Creative people, no entitlement, no rage, no stroller Nazis.”

And now? “I’m just happy I don’t have to leave the neighborhood to go to Sur La Table.”