Jerry Cowley, aquatic safety manager at the Silverton Hotel-Casino, interacts with children as an underwater Santa Claus at the casino's aquarium in Las Vegas.

LAS VEGAS - Las Vegas has mostly shelved its attempt to rebrand itself as a family-friendly wonderland. But there's one exception: the dreaded holiday season, when visitor numbers crater and room vacancies soar.

In an attempt to lure tourists, Las Vegas casinos are staging increasingly elaborate holiday events.

The Bellagio has again transformed its conservatory into a faux winter wonderland featuring a 42-foot-tall Christmas tree, a life-sized candy house, a walk-through snow globe and topiary polar bears, all a few paces from the gambling floor.

The casino's famous dancing water fountains are leaping to Christmas classics, and tourists are taking photos with a 250-pound chocolate Grinch.

The Forum Shops at Caesars Palace is showing its Christmas cheer with "Elf Aquarists," divers in elf-style wet suits who feed the aquarium's tropical fish during daily shows.

Perhaps the most elaborate of all the exhibits is "Winter in Venice" at the Venetian, which the casino advertises as a public gift in banners strung outside its ersatz Italian facade.

December is traditionally the slowest month in Las Vegas. Last year, tourist volume fell from a high of 3.53 million visitors in March to a low of 3 million visitors in December, according to the Las Vegas Convention and Visitors Authority. November and January didn't look much better.

Keith Salwoski, spokesman for the Venetian and Palazzo hotel-casinos, said the winter extravaganza, now in its third year, has helped convince families to seriously consider a holiday vacation to Sin City.

"Every photo that is shared during the holidays, for instance, helps to change the perception of the destination for the Christmas traveler. Suddenly, spending Christmas in Vegas is on the radar of travelers," he said.

Beautifully costumed actors stroll around the casino halls, greeting children and posing for silly photos with adults. Outside, a 65-foot Christmas tree made of lights shines like a beacon, tempting pedestrians to come inside.

Helen and Bob Harrison spent a recent afternoon gazing at a cluster of white birds and poinsettias arranged in front of an indoor waterfall near a bank of slot machines at the Venetian. The Wichita, Kan., couple was celebrating their 60th wedding anniversary, and had decided to spend the week visiting all of the Strip's Christmas exhibits.

"I used to work in a flower shop, and I just love this. The design that goes into it - we don't have anything like that in our city," Helen Harrison said. "It's nice to not have to go to Europe to see all this stuff; it saves on travel."

The Cosmopolitan Las Vegas, a few blocks over, has doubled the size of its rooftop skating rink this year. Chief marketing officer Lisa Marchese said the casino is going for a "ski lodge perched over the Las Vegas Strip" aesthetic. Skaters can huddle around fire pits and buy s'mores kits for $14 (It's still the Strip, after all).

The rink at the Cosmopolitan is just one of several designed to entice desert visitors to casino properties. Caesars Palace, the Venetian and the Gold Spike are among those offering skaters an opportunity to lace up their boots for ice, real or artificial.

While most Las Vegas spectacles are designed to dazzle and erase the memory of home - with all its constraining social mores - the Christmas installations aim to remind tourists of their childhood.

"It's nostalgic," Marchese said. "I don't care where you grew up, I think everyone romanticizes the notion of skating in the winter."