In 1967, Atlanta architect and developer John Portman gave the city — my city — a certified civic symbol. It wasn’t as tall as the Empire State Building or as grand as the Golden Gate Bridge. But the new Hyatt Regency Atlanta, with the first-ever atrium lobby and a revolving restaurant on the top floor, shattered the old hotel mold. At the Hyatt, hallways had turned into balconies, and guests were encouraged to indulge in some “indoor sightseeing” — watching people ride up and down the glass-bubble elevators, for example, or sip cocktails amid the ferns and fountains below.

More than 40 years later, the atrium lobby is ubiquitous, and the Hyatt still stands, its blue-domed saucer top now dwarfed by the dozens of skyscrapers all around it. Atlanta may be the poster child for urban sprawl; commutes here are still some of the longest in the country. But in recent years, “the ATL,” as it’s known, has gone vertical, sprouting new luxury hotels, high-rise condos and some of the tallest office towers in the world. And nowhere has that transformation been as striking as in the four fashionable square miles of Midtown.

Around the time the Hyatt Regency was going up Downtown, Atlanta’s Midtown was “the hippie strip,” a commercial dead zone with a small museum, a handful of restaurants and turn-of-the-century houses in various states of disrepair. Crime was on the rise, the suburbs were booming, and the city’s population had begun a two-decade decline. With the singular exception of Colony Square — the first mixed-use development in the South and a bellwether of things to come — Midtown had fallen into decay.

By the mid-1980s, though, things began to change. It all started with the 50-story One Atlantic Center, for many years the tallest skyscraper in the Southeast. I was 9 years old when it went up on the corner of West Peachtree Street and 14th, a few blocks from our house, and I can still recall watching from the front yard as a helicopter lowered the shiny copper spire into place.

In the two decades since, Midtown has added some 22 million square feet of office space, becoming home to the corporate headquarters of a slew of Fortune 500 and 1000 companies, including Equifax, The Coca-Cola Company, AT&T, Invesco and Wachovia, to name just a few. Law firms filled much of that office space, along with a number of blue-chip technology firms spawned by the Internet boom. And, of course, the banks came, too — even Atlanta’s branch of the Federal Reserve, which vacated a Downtown property it had occupied since 1918.

But that’s history. The mixed-use Midtown Mile is what matters now — and will to the 20,000 people expected to move into the area over the next seven years. Modeled on Chicago’s Magnificent Mile and New York’s Madison Avenue, the project aims to add 1 million square feet of street-level retail to the 14 blocks of Peachtree Street between Downtown and Buckhead. The latter, a leafy, Southern version of Beverly Hills full of stately mansions and high-end malls, has long been the region’s most renowned shopping district with the highest concentration of luxury boutiques in the United States.

Buckhead, too, is on the brink of big change. “The Streets of Buckhead,” a $1.5 billion project by Ben Carter Properties, developer of the mammoth Mall of Georgia, is set to transform the area’s once raucous bar district into a haute couture retail zone in shades of Rodeo Drive with “shops along sidewalks to browse and sashay.” Marking a first in Atlanta’s car-only culture, it will be possible to walk from designer boutiques — Oscar de la Renta, Loro Piana, Domenico Vacca — to one of the area’s 14 fine-dining restaurants, two 5-star hotels or hundreds of million-dollar condos.

Yet by far Atlanta’s biggest project — and the one with, arguably, the greatest potential to enhance the city — is the multi-faceted BeltLine. Long before Atlanta grew up, it grew out, resulting in disconnected pockets of development. By combining green space, pedestrian trails, well-preserved historic homes and other structures and transit along a 22-mile loop of rail segments, the BeltLine seeks to rein in the sprawl and forge a more cohesive city accessible to residents and visitors alike. The largest, most comprehensive urban redevelopment project currently underway in the United States, the BeltLine is expected to generate some $20 billion in economic development over its 25-year span as well as more than 30,000 new full-time jobs.

It’s probably safe to say that neither Midtown nor Buckhead nor any of Portman’s palatial creations would be here today if it hadn’t been for one William B. Hartsfield. In 1926, the air show promoter-turned-city alderman lobbied for Atlanta’s designation as a site along the proposed federal airmail route from New York to Miami. For a time, it looked like regional rival Birmingham might win the bidding. But as anyone who has ever visited Hartsfield-Jackson Atlanta International Airport (ATL) well knows, that didn’t happen.

Last year, Hartsfield-Jackson retained its ranking as the world’s busiest airport, processing close to 1 million flights and 90 million passengers. And if capital upgrades are any guide, those numbers aren’t going down anytime soon. In addition to a sixth runway, construction is underway on the new Maynard H. Jackson International Terminal. Named for Atlanta’s first African-American mayor, the airport’s $1.6 billion project mirrors the growth of its biggest client, now the world’s biggest carrier, Delta Air Lines.

With its 2,500 direct daily flights and 250 destinations, Delta’s economic impact on Atlanta is immense, an estimated $13 billion a year. And there may be nothing more business-friendly about the capital of the South than the accessibility that presence affords; approximately 80 percent of the U.S. population is within a two-hour flight. Atlanta may be growing in new directions — up rather than out, together instead of apart — but the engine driving that growth is the same one it’s always been.

Diversions

No mountains. No beaches. No Broadway. To the uninitiated, Atlanta could seem to be lacking in the basic ingredients of a good time. But millions of visitors know better, including the more than 6 million who’ve passed through the Georgia Aquarium, 225 Baker St. N.W., tel 404 581 4000, the world’s largest, since it opened in 2005 as a gift from The Home Depot co-founder Bernie Marcus. Already featuring more than 500 species, the aquarium will add one more when a new $110 million dolphin exhibit opens in 2010.

From there, you can search for the “secret formula” at the recently reinvented World of Coca-Cola, 121 Baker St. N.W., tel 404 676 5151, with its ever-flowing fountains of soda from around the globe, or tour the studios at CNN Center , where the nonstop news cycle was born.

Caffeinated and caught up on current events, you’re ready for a lesson in Atlanta’s rich civil rights history at the must-see Martin Luther King, Jr. National Historic Site, tel 404-331-6922. The 70-acre site includes the Sweet Auburn Historic District and Ebenezer Baptist Church, where King’s sermons inspired the masses.

For more of Atlanta’s past, head to the Margaret Mitchell House, 990 Peachtree St., tel 404 249 7015, in Midtown, where from her kitchen table Atlanta’s most storied author wrote Gone with the Wind, the 1937 Pulitzer Prize-winning saga of the South’s defeat in the Civil War. Exactly 30 years later, the Woodruff Arts Center, tel 404 733 4200, home to the High Museum of Art and the Atlanta Symphony Orchestra, opened just a few blocks further up Peachtree. Already the largest arts center in the Southeast, the Woodruff is soon to add a new Santiago Calatrava-designed Symphony Center to house the Grammy Award-winning orchestra.

Classical music, modern art, Southern literature. It’s all very nice, but let’s be honest. You’re working, you’re stressed — what you need is some retail therapy. Schedule your first session at Buckhead’s Lenox Square, tel 404 233 6767, Atlanta’s oldest and largest mall, with four floors, five restaurants and more than 200 stores. On the other side of Peachtree, Phipps Plaza features 100 specialty shops, including a two-floor Barneys and a 14-screen AMC movie theater.

With much of Buckhead under construction, the charming Virginia Highland neighborhood is where Atlanta kicks back amid a collection of art galleries, antique shops, bars, restaurants and bungalow homes. Stop for some blues at Blind Willie’s, tel 404 873 2583, or blow off some steam in Piedmont Park, Atlanta’s 189-acre “common ground,” with sprawling greens, jogging trails, a new pool and some of the best views of this city’s ever-evolving skyline.

Lodging

Four Seasons Hotel Atlanta
Located in Midtown, this 244-room classic comes with elegance, skyline views and major meeting space. 75 14th St., tel 404 881 9898, $$$$

The Mansion on Peachtree
Enjoy Southern-style luxury at this 5-star boutique, where the entire third floor is devoted to the flagship spa of Lydia Mondavi. 3376 Peachtree Road, tel 404 995 7500, $$$$

St. Regis Atlanta
Atlanta’s ne west hotel, the stately 151-room St. Regis in the heart of Buckhead, features massive meeting spaces, Southern gardens and lavish décor throughout. 88 W. Paces Ferry Road, tel 404 563 7900, $$$$

Dining

Bachanallia
Husband and wife chefs Clifford Harrison and Anne Quatrano have racked up awards for their contemporary American allorganic cuisine. 1198 Howell Mill Road, tel 404 365 0410, $$$$

Bone’s
“Best of Atlanta Steakhouse” for 16 years running, this Buckhead institution combines superb food and service for the best business dinner in town. 3130 Piedmont Road, tel 404 237 2663, $$$$

One Midtown Kitchen
Set in a renovated warehouse, this Midtown hotspot attracts a fashionable crowd all week with seasonal ingredients cooked with gourmet flair. 559 Dutch Valley Road, tel 404 892 4111, $$-$$$

At Home With Jef Gram
Atlanta businessman and owner of Cayo Espanto, Belize

You’re a longtime Atlanta resident. What are the biggest changes you’ve seen in the city?
The tall buildings are probably the most obvious change. They’re suddenly everywhere. But it’s also been interesting, and very good, to see land planning on a scale as large as the BeltLine project, which could reshape Atlanta in dramatic ways. There’s already been progress in that direction — for example, Georgia 400 being connected with I-85 South — and I hope that continues. I hope it’s not just “pie-in-the-sky” talk.

What makes Atlanta such a good place to do business?
I think the things people like about it are not a whole lot different from what they like in a great vacation spot: the weather, the restaurants, the parks, especially Piedmont and Chastain. In these tough economic times, people’s priorities have changed; the most important thing nowadays is quality time with family and friends. And whether it’s in Piedmont Park or Cayo Espanto, they want to be somewhere they can get the most out of that time. The other stuff just becomes less important.

Do many of your guests at Cayo Espanto come from Atlanta?
Yes, partly because Cayo Espanto is so close. The direct flight from Hartsfield-Jackson to Belize City takes about three hours. In about five minutes our staff transfers you and your bags to the boat, at which point we hand you an ice towel and take your drink order. So less than four hours after you leave Atlanta, you’re in your private waterfront villa on a private island, drink in hand.