NEW YORK (CNN/Money) - Las Vegas has hit the jackpot by returning to its roots.

The city that attracted billionaire Howard Hughes and gangster Bugsy Siegel decades ago made a huge push in the 1990s to clean up its image and attract families on vacation.

But now all bets are off on Las Vegas as a family destination.

With drag queens dominating the stages of New York-New York and sexy cabaret dancers strutting their stuff in a lion's den, sin is back, and Sin City is flaunting it.

"There's some appeal for families, but Las Vegas is a destination that's best suited for adults," said Marina Nicola, a spokeswoman for the Las Vegas Convention and Visitors Authority (LVCVA).

In fact, Las Vegas has shelved its family-friendly image and went full force last year with a slew of TV spots featuring the steamy tag line, "What Happens Here, Stays Here."

With many of the ads showing the naughty nature of Vegas, tourists responded.

Nearly 3.3 million people visited the city in March, up 9 percent from the same period a year ago, making it the busiest month since the Sept. 11 attacks and the second busiest ever, the authority said in a report.

The jump in tourism has helped revive the city's job market and the local economy, which were badly bruised by Sept. 11.

In the top ad, the elderly couple gets ready to go out but tells their family they're staying in. The bottom ad shows a young couple claiming their luggage from a hotel concierge after spending 36 hours in Vegas without even checking into their room.

"Over 15,000 gaming jobs were lost after 9-11," said Somer Hollingsworth, president of the Nevada Development Authority. "It turned our state budget upside down."

But booming tourism brought 36,000 jobs back to the city last year, 6,000 of those in the gaming industry, Hollingsworth said.

And even though it's bounced back, Sin City isn't standing still. The LVCVA rolled out a new ad campaign in February, and forecasts are that 36 million visitors will come this year, topping the previous record of 35.8 million, set in 2000.

The tourism authority also said the city has about $5 billion to $6 billion in construction or renovation projects underway.

"We haven't seen anything like this in the past few years," said Nicola, "especially when our economy is still in a recovery."

Las Vegas, the largest city in Nevada, was never this confident about being a playground for grown-ups before.

Back in the 1990s, the gambling haven had something like an identity crisis when some of the biggest casinos on the Strip decided to bill their resorts as Orlando-type theme parks aimed at families, but replete with slot machines, blackjack tables, roulette and other games.

The MGM Grand and Treasure Island, both owned by MGM Mirage (MGG: Research, Estimates), made big bets on attracting families.

The MGM Grand on the Vegas Strip closed its theme park two years ago and added an age-restricted show called "La Femme."

MGM, for one, spent $100 million on a 10-acre theme park behind the property famous for its gold statue of the 45-feet tall MGM Lion sitting atop the hotel's entrance.

"They were trying to capture the baby boomers who often travel with extended family," said Rob Dondero, executive vice president of ad agency R&R Partners Inc., which produced the "What Happens Here" campaign.

The effectiveness of the family campaign was "very brief," Dondero said.

MGM replaced the theme park with a series of luxury villas two years ago as new management admitted the theme park had failed to attract enough visitors, said Alan Feldman, spokesman for MGM Mirage.

Management at the time didn't realize that "Las Vegas has been and will always be an adult destination," said Feldman.

A nude cabaret show called "La Femme" was added to the resort last year, he said, noting it was an "age-restricted show, catering strictly to adults."

The hotel-casino is also getting a huge $750 million facelift that will add a night club, bars and restaurants.

Treasure Island, meanwhile, has replaced its live-action pirate spectacle with a performance that's more like a wet T-shirt contest.

MGM Grand and Treasure Island aren't the only ones that have stripped down to the roots of adult entertainment.

Cirque du Soleil, the French-Canadian circus troupe, created "Zumanity," which features a drag queen emcee and two women swimming nude in a fishbowl, for the New York-New York casino-resort last September.

Joey Arias, in the top photo, is the drag queen emcee on Cirque du Soleil's "Zumanity." The show also features two women swimming nude in a magnified fishbowl.

"My feeling was that the show might take a year or so to find its market, but it only took a couple of months," said Michael Bolingbroke, senior vice president of shows at Cirque du Soleil. "Well before the end of last year, we were selling out every night."

While tourism has bounced back, city officials said the slow economic recovery and the U.S.-led war in Iraq have kept some overseas visitors away.

"We had the economy. We had the Iraqi war. We had SARS. Those things took a huge chunk out of the number of our Asian visitors last year," said LVCVA's Nicola. Tourists from abroad, about 11 percent of visitors in the late 1990s, slipped to 9 percent last year.

The city is also to some extent a victim of its own success: some travel planners see it as too distracting, and not a place where corporate meetings will work.

"There are still some perceptions that attendees would do nothing but play while they are here," said Nicola. "It's not a huge problem, but that's one issue we've had to deal with," she added.

Wynn Las Vegas, developed by casino mogul Steve Wynn, is due to open in April 2005 in time for the city's centennial next May 15.

The hotel-casino will be the world's most expensive to build, costing about $2.4 billion, with 2,700 rooms, said Nicola.

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"The launch will be watched closely by Wall Street," she said, since the project will be the first big resort on the Strip in five years -- possibly marking the start of a new wave of casino development.

The Fashion Show Mall, the largest shopping center on the Vegas Strip, is finishing up a major expansion that will cost about $1 billion, said Nicola.

"Just when you thought the city has reached its limit, something bigger and better is getting built," said R&R's Dondero.