“The cab driver hugged me and told me everything was going to be okay,” said Dee Wedemyer, recalling her move uptown one evening last summer, when she lugged her belongings from an apartment in serene Tudor City to the far-from-fully renovated Riviera on 157th Street in lower Washington Heights. “He’d seen where I’d been living, and he was worried about where I was moving.” A former editor with the Sunday real estate section of the New York Times, Ms. Wedemyer had lived on Park Avenue and Roosevelt Island, and in Hell’s Kitchen, but this was farther north than she had ever envisioned.

Built in 1910, the Riviera was designed by architects Rouse & Goldstone to “evoke a sense of stateliness and romance,” wrote historian Michael Henry Adams in his book “Harlem Lost and Found.” But with scaffolding hiding its handsome masonry and blocking its lower windows, the Riviera that night looked anything but romantic to Ms. Wedemyer, who had paid just under $400,000 for her one-bedroom, one bath, 1,100-square-foot apartment. The once grand main entrance on Riverside Drive had been closed long ago, replaced by a plebian side entrance. Inside was a Plexiglas cage for the doormen and guards, like a public school in a bad neighborhood. Upstairs, her spirits sank further. Her apartment was filthy (the super had failed to clean it) and without electricity (the super had forgotten to turn it on). The “hideous kitchen” had no gas.

Yet a few months and about $85,000 later, she invited 40 friends to brunch on a beautiful Sunday in April to toast the sparkling, white-walled, completely reconstructed apartment she has made her home. She had shopped for the party at Fairway on 125th Street (a $6 ride in a gypsy cab), and ordered Dominican food from D’Vinci Restaurant on St. Nicholas Avenue.

Downtowners mingled with Riviera residents, discussing the neighborhood as if it were an admired, exotic destination. Gretchen Long, the 92-year-old widow of the Broadway performer and lyricist (“Bubblin’ Brown Sugar”) Avon Long, moved up from 114th Street in 1983. An artist, she paints by the light that streams in through a dozen north- and west-facing windows. Another Riviera neighbor, Jon Esman, helpfully told the downtowners, “An apartment in this line should go for a little less than $700,000 these days.”

An old-timer, Mr. Esman bought his 1,200-square-foot, “convertible one-bedroom” for $95,000 in 1988. But in case anyone thought a 700% return was excessive, he added that three years after he bought the apartment, he found that it couldn’t be sold.

“That year was the bottom of the barrel,” he said. “Guys thought they had a right to mug you. No one was buying in this neighborhood.” Drug dealers swarmed the streets, and shootings and assaults were a regular occurrence. In 1994, the 33rd Precinct reported 31 murders, 44 rapes, 683 robberies, and 766 burglaries. Those days are gone. Police department statistics show that violent crime has declined 62% since then, with murders down 84% and burglary 77%.

In hindsight, it’s amazing that an area as beautiful as Audubon Terrace ever decayed. With its imposing apartment buildings high above the Hudson River, its parks, public spaces, and excellent public transportation, it is a remarkably pleasant and efficient place to live. The terrace’s residents are making up for lost time by lobbying the city to designate a historic district extending between 155th and 157th streets and from Amsterdam Avenue to the Hudson.

The complex that lends the area its name was carved out of John James Audubon’s 19th-century estate and game preserve by Archer Milton Huntington, a philanthropist who had inherited a railroad and shipping fortune. After establishing the Hispanic Society of America to promote Spanish culture through a museum and public library, he hired his cousin, Charles Pratt Huntington, to design its Italianate headquarters, which opened in 1908. His wife, Anna Hyatt Huntington, sculpted the equestrian statue of El Cid in the courtyard and the lions flanking the entrance.

Over the next few decades, his cousin also designed buildings on the terrace for the American Numismatic Society (1906-07), the Church of Our Lady of Esperanza (1909-11), the American Geographical Society (1909-11), and the Museum of the American Indian (1916-22). William Mitchell Kennedy of McKim, Mead and White and Cass Gilbert designed the Italian Renaissance Revival building of the American Academy of Arts and Letters (1923).

This grouping of buildings – as splendid as any in New York – slowly deteriorated through the 1960s. As patrons stopped coming, the institutions started to leave, starting with the American Geographical Society, which left in 1973, followed by the Museum of the American Indian in 1984. Yet the remaining institutions are extraordinary.

The Hispanic Society houses the finest collection of Spanish art outside Spain, says director Mitchell Codding. The first painting a visitor sees on walking through the terra-cotta arches is Goya’s “Duchess of Alba.” Huntington was a century ahead of his time in trying to bring together art from the Spanish-speaking world. His museum has become the natural cultural anchor for the upwardly mobile immigrants and New Yorkers flocking to the terrace.

Brown Harris Stevens sales associate Edward F. Johnston III, who sold Ms. Wedemyer her apartment, says the neighborhood is the last bargain in Manhattan – where a family size apartment can be had for half the price of the Upper West Side. “You can buy a six-room apartment in the upper sixes in the Riviera,” he says. “That’s two bedrooms, plus a maid’s room, one bath, and full fireplaces. A couple of lines have eight rooms. And you look over Riverside Drive, which curves so nicely and gracefully inward here – the only spot on Manhattan where it does this.”

The Grinnell, across 157th Street, has a seven-room apartment on the second floor listed at $899,000. “If you go 50 blocks south,” says Mr. Johnston, “you’d pay over $2 million.”

In “Harlem Lost and Found,” Mr. Adams cites the $850,000 sale of a restored five-bedroom apartment in the Grinnell in 2000 as the highest price ever paid in Harlem (Mr. Adams uses generous boundaries). The apartment had rented for $1,000 a month in 1985.

While there’s little question Audubon Terrace is heading back to its origins as an upper-middle-class enclave, the neighborhood remains strikingly energetic and diverse, even by Manhattan standards – and it isn’t for everyone. “It’s fairly clean on Riverside Drive,” comments Mr. Esman. “But it’s a real zoo on Broadway, where people do a lot of hanging around, especially in the summer.”

Riviera board chair Vivian Ducat isn’t worried. She’s been watching the neighborhood for a long time and is confident that its future is strong. She nearly bought a 10-room apartment in the Grinnell for $200,000 in 1992. But the building was pretty rundown then, and the neighborhood just seemed unsafe. Instead, she and her husband bought a small two-bedroom on West 86th Street, though regretting the lost apartment uptown. They rectified this in September 2003 when they paid $850,000 for a lovingly restored, three bedroom, two-bath apartment on the top floor of the Riviera.

“With the elegant museum complex and the low open development along Broadway, this area looks like nothing else in New York. It feels like Boston,” she said. And while services and retail are not yet strong, she patronizes several neighborhood places, like Coogan’s Bar, where the pols like to go. “Plus we’re getting a green market in July,” she says happily. “Then we’ll have everything.”