Much of the faux frontier town in Bally’s Wild Wild West Casino has disappeared — hidden behind large, temporary walls.

It’s as if the cowboy-themed casino, like the real Wild West, is fading into history.

“It’s an eyesore now. It’s a shame. This was once one of the nicest casinos in town,” said Larry Sheetz, a Maryland tourist who was shocked when he and his wife, Nancy, recently visited the Wild Wild West for the first time in a year.

Bally’s Atlantic City, which opened in 1979, was formerly one of the dominant local casinos. However, its gambling revenue has slipped dramatically in recent years amid a downsizing of its casino space.

The Bally’s complex is an amalgamation of buildings and themes patched together over the years — the Wild Wild West, the modern, glass-covered Bally’s tower, the old Claridge Casino Hotel and the Victorian-era Dennis Hotel.

Parent company Caesars Entertainment Corp. began sealing off parts of the Wild Wild West in February 2012 to replace some of the casino space with new retail, dining and entertainment attractions.

At the same time, the lone remaining floor of the once three-story Claridge casino was completely closed down, also to make room for redevelopment into nongambling amenities.

More than a year later, nothing new has been built. Caesars Entertainment says it has no updates to announce on the Wild Wild West and Claridge redevelopment plans.

“We’re still meeting with potential partners and look forward to bringing new, nationally known experiences to the most famous address of Park Place and the Boardwalk,” company spokeswoman Katie Dougherty said in a brief e-mail.

Caesars Entertainment declined a Press of Atlantic City request to tour Bally’s with Kevin Ortzman, the casino’s senior vice president and general manager.

Bally’s is coming off a tough year, suffering a 22 percent decline in gambling revenue in 2012. Only Trump Plaza Hotel and Casino, down 25 percent, had a bigger revenue drop last year among Atlantic City’s dozen casinos. Bally’s finished 2012 with $296 million in total gambling revenue, fourth in the market.

As recently as 2004, Bally’s was the city’s top-grossing casino. In that year, it took in $644.7 million from its slot machines and table games. Borgata Hotel Casino & Spa grabbed the top spot in 2005, but Bally’s remained a solid No. 2 for four years. In 2009, Harrah’s Resort overtook Bally’s for second place. Bally’s slipped again in 2011, falling to fourth when Caesars Atlantic City notched third.

Customers complained that Bally’s has only itself to blame for its fall. They said management has gone too far in closing off sections of the casino hotel.

The Sheetz couple, of Bel Air, Md., had planned to sign up for a player-rewards card when they walked into the Wild Wild West, but changed their minds after seeing the vanishing landscape.

“Why bother?” Nancy Sheetz said. “There’s not much here now.”

Gus Markides and his brother-in-law, Lewis Hummel, both of Long Island, N.Y., lamented the Claridge’s demise. They sat in a restaurant not far from where the Claridge casino once was. Claridge’s former casino space is gone, sealed off by walls and locked doors, although the hotel remains open.

“It used to be beautiful. They had everything you ever wanted,” Markides said of the Claridge. “Now, everything is blocked off. It’s very frustrating. A lot of things that they’re doing aren’t very friendly to the average customer.”

The Claridge is one of the few remaining historic hotels dating to Atlantic City’s tourist heyday as the “Queen of Resorts.” When it opened in 1929, it was dubbed the “Skyscraper by the sea.” It was reinvented as a casino in 1981. But the Claridge’s time as a stand-alone casino ended when it was folded into the sprawling Bally’s complex in 2002 following an ownership change.

The Claridge formerly offered three floors of gambling, but it was reduced to just one level of casino space during a downsizing in 2009. Markides said the crowds became smaller as the casino shrank in size.

“We used to come here all the time,” he said. “Now, we usually go to Caesars. The Claridge is not what it used to be.”

In 2010, Caesars Entertainment invested $20 million into the Claridge to give its guest rooms a facelift and to revitalize its red-brick exterior. At that time, the company talked of possibly converting the 24-story Claridge tower into an upscale hotel property.

Christopher DiGeorge, a Philadelphia developer, sued Caesars Entertainment last year, claiming it reneged on a deal to have him transform the Claridge into a posh, Morgans Hotel Group-branded resort. Caesars has declined to comment on the lawsuit, which is pending in state Superior Court.