Clearly, brick and steel age more gracefully than the rest of us, because Oriole Park is about to celebrate its 20th birthday on Opening Day Friday and who can believe it is already the 10th-oldest ballpark in the major leagues?

Time does fly, in this case seemingly faster than an Adam Jones line drive or a Jake Arrieta heater. The stadium that changed the way stadiums are built was an instant classic. Now, it's simply the grande dame of the post-modern era of sports architecture, but its continuing impact on both baseball and Baltimore cannot be overestimated.

"Building Camden Yards was one of the most important things that happened to baseball in the last 20 to 25 years," Major League Baseball commissioner Allan H. "Bud" Selig said. "It changed the whole dynamic. It led to all these wonderful stadiums and allowed us to finally market our sport to its potential -- particularly the last five years of terrific growth.

"It set it all off. It never would have happened without Camden Yards. But I don't think anybody could really have understood how dramatically it was going to change the face of baseball and the Orioles."

It also changed the cityscape of Baltimore -- vastly broadening the appeal of the Inner Harbor area -- and was the giant first step in the development of a multisport complex that is among the most admired in the world.

The only thing that has changed over the past two decades is the context in which it is viewed both inside and outside the Baltimore area. There were those who suspected at the time that it would shake the American sports landscape, but for the diverse cast of characters who planned and designed Oriole Park, the mission was to assure that the Orioles remained in Baltimore and the stadium became a unique, organic component of the rejuvenation of the downtown area.

"We did envision a traditional, old-fashioned ballpark with modern amenities," said former Orioles president and CEO Larry Lucchino, who first proposed the concept of a ballpark that took baseball into the past and the future at the same time. "What we didn't know was that it would light a fire in the industry and cause other cities to seek similar ballparks, but that's exactly what it did do."

The impact on baseball architecture was almost immediate, and the impact on baseball economics would be dramatic.

Baseball author and political commentator George Will once called Oriole Park one of the three most important developments in baseball in the postwar era, along with Jackie Robinson's breaking the game's color barrier and the advent of free agency. Nothing that has happened over the past 20 years has caused him to change that opinion.

"It taught baseball to look backward," Will said. "We conservatives are always being told that you can't turn the clock back. Baseball did.

"We'd gone through the ghastly '60s and '70s period with those stadiums built for both baseball and football that were good for neither. You didn't know if you were in Pittsburgh, St. Louis or Philadelphia. You couldn't tell the difference."

There is plenty of credit to go around for what remains one of the architectural jewels of professional sports -- from architect Joe Spear and the large staff at HOK Sport (now known as Populace) to Orioles architectural consultant Janet Marie Smith to Maryland Stadium Authority chief Herb Belgrad and beyond. Even current Orioles owner Peter Angelos, who arrived on the scene after the ballpark opened, deserves some for heavily promoting "Camden-ization" as the answer to Major League Baseball's economic ills.

But clearly, the two biggest players in the drive to re-establish Baltimore as a major sports town and enhance the appeal of the Inner Harbor as a tourist destination were late mayor and Maryland Gov. William Donald Schaefer and -- ironically -- the current president of the Boston Red Sox.

"I've said this over and over," Lucchino said. "I had one original idea in my whole baseball career. It was to build a traditional ballpark for the Baltimore Orioles with modern amenities and conveniences so we could have the revenue to compete with the best teams in baseball."

Why there? Why then?

The architectural considerations aside, it is widely accepted that Camden Yards was truly conceived March 29, 1984, when Baltimore sports fans woke up to the staggering realization that their beloved Colts had skipped town in the middle of the night.

The Orioles, then owned by Washington attorney Edward Bennett Williams, were itching to move to a location that would be more accessible to fans in the D.C. area. Schaefer, clearly shaken by the departure of the Colts, initially pondered a major renovation of Memorial Stadium but soon shifted focus to building a multipurpose stadium closer to downtown that would satisfy the Orioles and help the city acquire an NFL expansion franchise.

It would take years to settle on the Camden Yards site and a major effort by the Orioles to convince the state to build a baseball-only facility, but it was those two decisions that became the keys to the tremendous success of Oriole Park.

The site allowed the stadium to blend naturally into the Baltimore skyline. The decision to build it for baseball only assured that the team would sign a long-term lease, which is where to start if you want to measure the true impact of Oriole Park on Baltimore.

The Orioles weren't planning to go anywhere, but they made it clear that they would sign only a series of one-year leases if the stadium were built for both baseball and football. Since the baseball team was real and a football team was purely hypothetical at that time, it was obvious the Orioles were holding most of the cards.

"We had to make sure that what happened to the Colts didn't happen with the Orioles," said Belgrad, the first chairman of the Maryland Stadium Authority. "It was important to satisfy the tenant and get a long-term lease. When [Lucchino] said he wanted an old-time traditional ballpark, I really didn't know what that meant. We were open-minded. He introduced that concept for the first time."

That concept, born of Lucchino's love of Pittsburgh's Forbes Field and baseball's other classic ballparks, seemed like a nice fit for Baltimore -- especially on a site that featured the old B&O Warehouse and was once home to a bar owned by the father of Babe Ruth -- but no one imagined how far it would reach beyond the old railroad hub.

"Not even a dream," Belgrad said. "None of us did because we were focused on what we needed in Baltimore because of what we had gone through. No other city had gone through the culture shock we had gone through when those moving vans pulled away from the Colts' facility in Owings Mills."

Was it worth it?

Camden Yards did not settle the debate over the appropriateness of using public money to build stadiums for highly profitable sports teams, though it certainly encouraged a lot of other cities to build their own versions of Oriole Park. There are valid arguments to be made about civic priorities, and they are amplified during this era of huge government deficits, but things were different then.

The ballpark cost about $110 million to build and was financed with bonds supported by the proceeds of the Maryland Lottery. Based on figures from the Maryland Stadium Authority, it has returned an annual average of $9.8 million in rent and entertainment taxes to the MSA to pay for debt service and maintenance.

Oriole Park also accounts for about $170 million per year in economic activity, according to the MSA's most recent economic impact report. In 2006, the year covered in that 2007 study, commerce directly related to ballpark events generated nearly $18 million in state and local taxes.

The city government realizes only nominal income from the ballpark, but the MSA also receives millions in rent from the office space in the Warehouse and millions more in parking revenue year-round. And the construction of Oriole Park was the beginning of a broader redevelopment of the site that includes historic Camden Station and M&T Bank Stadium.

Former Mayor Kurt Schmoke said last week that the project was always about more than just the economic implications. It was about continuing the transformation of the downtown area in a way that made financial sense but also changed the way Marylanders and the outside world looked at Baltimore.

"I just viewed it as a way to bring the metropolitan area together," Schmoke said. "I always considered that the region's downtown area. Particularly those years when [Oriole Park] was almost full every night, I would say the downtown merchants would say it had a positive impact. I think overall, just looking at the economics, it was worth doing. Then you add the intangibles to that and it's easy to make the case that it was something we should have done."

Gov. Martin O'Malley, who was a member of the Baltimore City Council at the time, remembers that there was the strong sense among city officials that the ballpark would be a major plus for the city and state.

"There was a clear understanding that this was a big accomplishment and a big change and one that, for the long term, was a change for the positive," O'Malley said.

It wasn't unanimous, of course, and there remain critics of the deal and economists who question whether the positive economic impact was enough to justify the construction of two state-of-the-art stadiums on the Camden Yards site.

Louis Miserendino, a visiting fellow at the Maryland Public Policy Institute, enjoys going to Camden Yards and doesn't dispute the grand proclamations about Oriole Park's architectural design, but he isn't convinced that the best way to revitalize a troubled city is by publicly funding fancy sports facilities.

"It's definitely a beautiful ballpark," he said, "but if we want to think of the ballpark as a tool for reviving the inner city, I think it falls short of that. If the stadium was built for that purpose, we were doing something that wasn't as effective as other alternatives."

Economist Richard Clinch of the Jacob France Institute at the University of Baltimore, however, contends that the argument in favor of including sports development as a component of Baltimore's downtown revitalization has largely carried the day.

"Baltimore, when it set out on this course, was one of the first cities to embark on a sports-led downtown development," Clinch said. "Baltimore focused on redeveloping the Inner Harbor, of which Camden Yards is a part, as critical to the goal of bringing more people downtown. Look at any of the textbooks [on urban redevelopment]. They are going to look at this as an innovative approach."

No one who has tried to buy a good ticket to a Red Sox or New York Yankees game can deny that the baseball park is a major tourist attraction. The economic survey commissioned by the MSA in 2007 confirmed that, estimating that about a third of Oriole Park attendees came from outside Maryland. The study also concluded that the ballpark supported nearly 2,500 jobs that generated $72 million in personal income.

"There are detractors," Clinch said, "but Baltimore was one of the first cities to do this and did it well. I think Camden Yards is unambiguously positive for the downtown area."

Something old, something new

There are a lot of reasons Oriole Park became the poster child for a new generation of stadium architecture and a national symbol of successful downtown revitalization, but most of the people involved point to the leadership of Schaefer, the vision of Lucchino and the political skill of Belgrad for the way the project came together to the satisfaction of everyone involved.

"The Orioles and the MSA were really good clients," said Spear, whose company had already designed the retro-style minor league ballpark in Buffalo, N.Y. "They had a view of the way they wanted to present the game of baseball. They had the strong opinion that baseball had lost sight of that in the '60s and '70s, when everybody thought, 'Why build two when you can build one multipurpose stadium?'

"When you think about it, those stadiums were round. Football fields are rectangular, and a real baseball park is shaped like a boomerang. A circle is not ideal for either one. I think they were bad for both sports."

Lucchino was driven by both a sense of nostalgia and the desire to create something truly special for the Orioles and Baltimore.

"What Larry cared about was to have the old-fashioned spirit of Ebbets Field, Forbes Field, Wrigley, Fenway and Yankee Stadium," said Smith, who served as Lucchino's architecture consultant through the design and construction of Oriole Park and is overseeing the ballpark's latest improvements. "What made those parks special was that they were woven into the neighborhood. They weren't sitting proudly above the city."

It was up to Smith and HOK to turn that vision into the unique (at the time) combination of old and new that allows Oriole Park to be as architecturally relevant today as it was on Opening Day of 1992. But the character of the ballpark might have been very different if not for one critical decision early in the design process.

"To think," Will recalls, "that there were people who seriously considered, and some advocated, tearing down that Warehouse."

The B&O Warehouse ended up being refurbished and stands as the most recognizable aspect of the ballpark complex. It serves as a magnificent backdrop behind the right-field and center-field walls and also -- from a more practical standpoint -- houses the Orioles' offices and other tenants that generate substantial rental revenue for the MSA.

"You always look for some symbol of the community that convinces the citizenry that the building could only be in Baltimore," Spear said. "The Warehouse was like having a natural waterfall or a stone bluff that was already there. It was a scale element that helped us. It was a way to make it seem familiar. The Orioles were looking for something iconic. With the Warehouse, the batter could step into the batter's box thinking, 'Can I break a window?'"

Smith said the Warehouse was the key to making the ballpark's old-time affectation feel truly authentic.

"When Larry said, 'I'd like an asymmetrical playing field,' I didn't think he wanted to produce a Disney version of Ebbets Field," Smith said. "The Warehouse allowed us to shape the ballpark diamond. By keeping the Warehouse, it forced the right-field line to be shorter, which was a good thing."

There is little remaining debate over any part of the architectural design and relatively little dispute about the wisdom of building a scenic, old-style ballpark that reflects the history and character of Baltimore.

"It's not only a jewel for the city," Schmoke said, "but for all of baseball."