Still, developers insist the concept of an upscale mixed-use community in the heart of the city remains intact.

"We've stayed very true to the vision," Rita Brandin, a vice president and development director for Newland Communities, said. "The umbrella of the design standards is what keeps us on track for each individual development."

The project, formerly called the "61 acres," is bordered by Bonneville Avenue, Grand Central Parkway and the Union Pacific Railroad tracks. The city obtained the parcel, once owned by Union Pacific, in 2000 by swapping 97 acres in a northwest Las Vegas technology park.

The price tag for the project is $6 billion and will include 10 million square feet of development if all phases are completed.

In addition to the Frank Gehry-designed brain institute, the project includes the Smith Center for the Performing Arts, a Charlie Palmer boutique hotel and the World Jewelry Center.

Also planned on the site are almost 2 million square feet of office/medical space, more than 5 million square feet of residential housing, 475,000 square feet of retail, two nongaming hotels, a hotel/casino and a park.

Brandin acknowledged that as projects such as the brain institute begin to take shape, while others are early in the planning stages, it is easy to think the focus has shifted away from a cohesive neighborhood and toward a bunch of individual developments that share nothing but a ZIP code.

"It absolutely is not getting fragmented," Brandin says. "Nothing could be further from the truth."

While new opportunities have spawned adjustments in planning, she said the essential mix of components, even within specific parcels, remains consistent with the vision presented to the city council by Newland in May 2006.

She pointed to the World Jewelry Center as an example.

When Union Park was in the planning stage, that specific building was not even envisioned as part of the project, she explains. But the plan did call for an office building on that site that would have a retail component.

As the World Jewelry Center went from being a massive dream to the realistic and vital part of the project it is now envisioned as, adjustments had to be made.

Instead of a parcel with 500,000 square feet of office space and 250,000 square feet of retail, the project is now planned with 1.7 million square feet of office space and 300,000 square feet of enclosed retail.

Design plans for the jewelry center indicate the signature tower will be more than 50 stories high and able to accommodate about 400 international wholesale jewelry dealers and manufacturers. The complex will also include an adjacent shopping promenade that will house 60 retail jewelers and a gem and jewelry museum.

It seems the more challenging facet of the project may be the residential component.

While the city has always envisioned residences on the site, the downturn in the housing market has brought out the skeptics regarding that phase of Union Park.

"Everyone reads the paper and listens to the news every day," Brandin said. "The pace of absorption for residential whether it's single family or multifamily has decreased dramatically."

Despite this, Brandin insists the residential developments, the first of which is expected to begin construction in the fall of 2008, are still an integral part of the project.

"It's not going away, Brandin said. "We're not going to give up on the residential."

Without the residential aspect, Brandin said the project would just be a shiny office park during the day and a quiet, vacant environment at night, which is not what anyone associated with the project wants.

Scott Adams, business development director for the city of Las Vegas, said he is confident the residential component of the project is still sustainable, based on the most recent housing numbers.

"Only the subprime market is currently being affected, which seems to consist of buyers with marginal credit," Adams said. "We don't think this is the market for buyers in Union Park."

Brandin confirmed that residential units at Union Park would range from about $300,000 to upwards of $1 million.

Mayor Oscar Goodman said his enthusiasm for Union Park is not limited to the projects on the site. He envisions a corridor, possibly along Bonneville Avenue, that will link the development to the rest of downtown.

"I think that's everyone's goal," Goodman said.

Goodman indicated Forest City Enterprises, which the city has chosen to develop the Queen of Hearts block along Main Street downtown, might also develop the corridor that would link the projects.

"That's a possibility," Goodman said. "I recently spoke with Forest City and they have some impressive plans for that area."

Goodman confirmed that a new City Hall is tentatively included in the plans. City leaders have long wanted to replace the existing City Hall at 400 Stewart Ave. and see the replacement building as a catalyst for the other facets of the project.

"It's sort of like a set of dominoes falling," Adams said. "If we can get the permanent City Hall site, it's kind of like the first domino to go down."

Cleveland-based Forest City is a premier urban retail developer that recently acquired a majority interest in the site and is also involved in discussions regarding a proposed casino development on two parcels at Union Park.

The company has established a local presence as the developer of the Galleria at Sunset in Henderson.

Brandin confirmed that Newland Communities has also begun "very early" discussions with Forest City about the Queen of Hearts project, as well as the parcels that would house the casino/hotel development.

"When I say early, it's about Forest City getting centered on the program requirements and the design requirements at Union Park," Brandin said. "We're also tying to understand what connection could be made from the west side of the tracks where Union Park resides, to the east side of the tracks."

In addition to the Lou Ruvo Brain Institute, Brandin says phase one of the project also includes infrastructure planning such as road and utility placement within the project.

Phase two, which is scheduled to begin next year will be highlighted by the beginning of construction on the performing arts center, the boutique hotel and the jewelry center.

The final phase of the project is scheduled to begin in 2009 and is targeted for completion by 2012.