MIAMI — After 20 years of retro-style ballparks since the opening of Oriole Park at Camden Yards in Baltimore, nearly all decked out with brick facades and calculated quirks that came to seem as predictable and interchangeable as the old doughnut-shaped arenas, Major League Baseball has its first unapologetic 21st-century stadium.


Lumbering and dizzyingly white in the Florida sun, the new Marlins Park is an elliptical concrete, steel and glass boulder looming above the low-rise houses and empty lots of Little Havana. With retail on the outside and a public plaza in front, it’s designed partly to gin up some street life. Economic development is supposed to follow — that was the rationale for the public financing that covered most of the $634 million project ($515 million for the park itself) and contributed to the recall of Miami-Dade County’s mayor. Cities are always building new stadiums with the justification that they’ll catalyze the local economy. They rarely do.


At the same time, the ballpark is unlikely to satisfy aficionados of the latest trends in architecture, but it is nonetheless a modern building, with genuine panache, as opposed to another pastiche. Give the team’s owner, Jeffrey Loria, credit. An art dealer, he cared more than most about aesthetics and took a gamble — part old-school civic improvement plan, part marketing strategy — that Miamians will recognize themselves in the stylishness of the place.


He has festooned concourses and stairwells with art, photographs and sculpture. Most fans will no doubt focus more on the grass field, air-conditioning and retractable roof, which slides over the entry plaza onto slender, palm-shaped pillars, illuminated by pulsing lights. The roof isn’t likely to be opened for more than a dozen or so games a year, but even when it is closed, there are sweeping views of the city skyline through 60-foot-tall windows.


The challenge now will be filling the park’s seats. With a capacity of 37,442, this is one of the smallest arenas in the big leagues, but Miamians in droves have notoriously stayed away from Marlins games. Mr. Loria and the city are banking, as so many other owners and cities have, that a new stadium can change a team’s and a neighborhood’s fortunes.


Can it? The Miami Marlins, until this year the Florida Marlins, have labored since their inaugural season in 1993 in a 75,000-seat suburban football arena, where the Dolphins play, which can be as much as an hour’s drive from downtown, with lousy sightlines, crippling summertime humidity and no roof. The Miami Herald’s Marlins beat reporter, Clark Spencer, told me on a recent night that he used to pass the time with colleagues in the press booth, counting attendance.


“Once we counted 80-something people,” he said, “and that included some confused foreign tourists.”


Mr. Loria, who took over in 2002, argued that it was pointless to spend money on top players without a domed stadium. Detractors said he was blackmailing the city into paying for a new park, meanwhile pocketing revenue-sharing millions from other teams that were meant to go toward a beefier payroll.


But then in 2007, Miami officials consented to a new stadium on the site of the former Orange Bowl, a couple of miles from downtown. The city provided the land and $13 million. Miami-Dade County paid nearly $350 million for the bulk of construction, with the Marlins kicking in $161.2 million. The pliant architecture firm Populous, formerly HOK Sport, which designed Yankee Stadium and nearly every retro ballpark during the last two decades, was hired to do the architecture.


Orel Hershiser, the pitcher turned ESPN analyst, got in first dibs as critic on opening night when, apropos the swooping “Star Trek” curves on the outside, he said that the stadium looked “like a cruise ship had a baby with a spaceship.”


Almost endearingly, when we met Mr. Loria countered with a few wishful comparisons to the Getty Center in Los Angeles and Frank Lloyd Wright’s Guggenheim Museum. He said the inspiration for the stadium’s electric color scheme, with its fluorescent-green outfield wall, was the palette of the Spanish painter Joan Miró. Public art and native plantings are meant to lend his building’s exterior what might be called an aspirational gravitas.


Inside Mr. Loria has also installed giant reproductions of paintings by blue-chip modernists like Roy Lichtenstein on or near the main concourse, called the Promenade, amid a souk of food stalls hawking $12 mahi-mahi tacos and $14 Cuban sandwiches. Nobody seemed to take much notice of the art the other night, fans clustering instead four-deep before a bobble-head-doll display. But Mr. Loria professed not to care. The goal is a mix of visual distractions.


These include two narrow saltwater aquariums behind home plate, giving off a bright blue glow. The intended spirit is light-hearted. For the same reason Florida’s hockey team never installed a panther cage in its rink, it’s now clear why no one had put an aquarium in a backstop before. Animal rights activists were traumatized after the team tested the glass with a pitching machine.


The game aside, the main attraction is clearly the kinetic sculpture by the Pop maestro of kitsch, Red Grooms, in left-center field: marlins spin, flamingos flap, and water splashes whenever a Marlin hits a homer. Miamians have been competing to come up with a name for it (the Marlinator and the Marlinstrosity are two, so far). This over-the-top gizmo is to the Mets’ homely home-run apple what the video game Call of Duty is to a jack-in-the-box. Considering how few homers have been hit so far, the fences might need to be brought in before too long to make sure it is exercised.