Baseball parks are on our minds these days.

One in particular: The Washington Nationals' home-to-be in Southeast D.C., due in the spring of 2008. It will be the most important piece of civic architecture in the city in the first decade of the 21st century. Nothing else comes close.

So, after the fiasco of losing the Frank Gehry-designed addition to the Corcoran Gallery of Art, and the ridiculous rejection of the Norman Foster-designed glass roof at the Old Patent Office Building, Washington still has a chance to shine.

That is chance as in opportunity, and chance as in chancy. When city officials went looking for a design team last winter, they emphasized that the city desired, and deserved, a ballpark that was at once urban, welcoming to pedestrians and friendly to the environment. And, also, it was to be "forward-looking" and "iconic."

The word iconic is relatively new to architecture. It is used (or perhaps misused) to describe memorable buildings that stand out from the norm to become "icons" of a given place. The Eiffel Tower is an icon of Paris. Gehry's, undulating, titanium-clad Guggenheim Museum in Bilbao, Spain, is the best known of the new architectural icons.

Thus, when the word iconic is associated with a stadium design, one thinks immediately of such soaring hits as Santiago Calatrava's Olympic Stadium, which became the television "icon" of the 2004 Summer Games in Greece.

Or of the design by the Swiss firm Herzog & de Meuron of the main stadium for the 2008 Olympics in Beijing -- an elegant, swirling mesh of concrete ribbons that resembles, in renderings, an immense bird's nest.

Or of the same architects' exuberant Allianz Arena in Munich, which will be a star attraction at next year's soccer World Cup. With its facade of luminescent, diamond-shaped, polymer cushions, it is like an enormous, irresistible cocoon.

Ours is, in fact, an exhilarating time for sports architecture. Many similarly ambitious, "iconic" stadiums have been built or designed worldwide. Stadium design is catching up with museum architecture in the global search for civic symbolism and design originality.

The quality of its architectural offerings is one reason why London pulled off its surprise victory in the competition to host the 2012 Olympics. The jewel in the British package was the Aquatics Centre designed by Baghdad-born, London-based architect Zaha Hadid -- an astonishingly beautiful concept for a building that rolls along the landscape like a series of waves.

"Hadid's exceptional winning design gives a taste of just what we can offer," bragged London Mayor Ken Livingstone. These days, British politicians are quick to brag about the country's splendid new sports architecture. Referring to the new Wembley soccer stadium with its electrifying steel archway, due to be completed next year, British Prime Minister Tony Blair burbled, "There is no doubt this is going to be the most spectacular stadium in the world."

Will Washington's politicians be able to make similar boasts -- and back them up -- about the new D.C. stadium?

Let's hope so, but don't bet on it. After all, baseball stadium design has, in a sense, been backward-looking ever since Oriole Park was unveiled in 1992. And, the architectural firm that designed the Baltimore stadium, HOK Sport + Venue + Event of Kansas City, was chosen in March to lead the design team for the Washington ballpark.

But HOK Sport is not wedded to the retro look. The firm collaborated with Pritzker Prize laureate Foster on the Wembley design, for instance, and with New Mexico architect Antoine Predock on the design of San Diego's expansive new baseball stadium, which opened last year. It played a leading role in the design of Stadium Australia (now Telstra Stadium), the main venue for the 2000 Olympics.

(In the Washington effort, HOK is joined by the D.C. firm of Devrouax & Purnell Architects. Polshek Partnership Architects, the New York firm whose design for the new Newseum is under construction on Pennsylvania Avenue, was hired by the D.C. Sports and Entertainment Commission to join the design team "in an advisory role," according to commission head Allen Lew.)

In any event, it's clear by now that the retro look pioneered by HOK in Baltimore has run its course. And we should remember, too, that there still is a lot to learn from Oriole Park. The Baltimore stadium remains a great place because the architects got the fundamentals right, from the column-free seating bowl to the spacious concourses to glorious Eutaw Street.

Another reason Oriole Park ranks high on the civility scale is that, like the newer ballpark in Pittsburgh (also an HOK Sport design), it provides a superb local view. You see the skyline and you know where you are.

In Washington, of course, we don't have a skyline of skyscrapers but we do have the Capitol dome and the Washington Monument. They are our city's supreme architectural icons. Clearly, the new ballpark should take advantage of this potential view and not be oriented, as some have advocated, toward a view of the Anacostia ridge.

There are, admittedly, a few challenges. The location of the new ballpark, on a large block bounded by South Capitol, First, N and O streets SE, prevents a clear centerfield framing of the monuments. This is because, thus oriented, the stadium would allow the afternoon sun to shine directly in a batter's eyes -- not helpful to the game. Another reason is that, eventually, South Capitol Street will be lined with buildings as high or even higher than the stadium itself.

Nonetheless, the architects ought to do everything in their power to catch as much as possible of the monumental Washington view. They could, for instance, cheat a little bit on the east-northeast orientation of the playing field recommended in the official rules of Major League Baseball, pushing it just a tad toward the west. And they could perhaps slice and dice the left field stands to accommodate the view in interesting ways.

There are other site constraints, as well. The Anacostia Waterfront Corp. strongly and wisely recommends a major entryway facing north, toward the nearest Metro station on M Street at Half Street SE. And it wants street-facing retail activities on the ground-floor levels of the stadium's N Street and First Street facades. The South Capitol Street side will be a special challenge. It will have to possess both the dignity and liveliness worthy of a great boulevard. (Don't laugh. There is a serious plan to transform the ugly street, and the ballpark will begin the transformation.)

And then there are the constraints of form. Most of the stunning new stadiums are designed for soccer, track and field or other sports that fit comfortably within the traditional stadium shape -- the oval. This shape (or variations thereon) is eminently suitable to the structural engineering feats that are the hallmarks of these new icons.

A baseball field, a right triangle with an open, rounded outfield where the hypotenuse would be, does not demand such rigid a structural frame. Its very looseness can be a virtue, as we see in the new San Diego ballpark, where the centerfield stands merge almost seamlessly into a public park.

Thus, an iconic baseball stadium would have its own look and feel. The challenge is to combine the game's old-time civility with the excitement of 21st-century design.

Yes, there should be a sense of striking inevitability about the design. It should fit the spirit of its time, and add excitement and surprise to its particular city and site. It should be a model of environmental responsibility. It will need a certain elegance and grace in the engineering. Excellent sight lines and visitor amenities are essential. And it should be, recognizably, a baseball stadium.

If we get all of that, we'll have our icon.

Sports architecture such as this stadium design for the 2008 Olympic Games in Beijing provides an opportunity for cities to build unique symbols. Washington has such a chance now with the Nationals ballpark to be built in Southeast.The London Aquatics Centre has an Olympic-class design. San Diego's Petco Park includes outside-the-box features.Oriole Park at Camden Yards set the standard for retro-style ballparks.