A pop-up outdoor event space on the once-polluted Miami River near a highway overpass is transforming a slice of rebuilt shoreline into a seemingly unlikely party destination for celebrities and tourists, marking the latest push to use a neglected waterway to spark real estate redevelopment in a major U.S. city.

The owner of Wharf Miami, Alex Mantecon, won voter approval in 2016 to build four restaurants on the site at 114 SW North River Drive . But with tenants hesitant to commit to the concept, Mantecon replaced the seawall and launched the open-air venue as a two-year test to show the parcel’s potential.

Today, Wharf Miami is filled most nights with customers from the city and surrounding area, and it’s not unusual to spot professional sports stars or models in the crowd. Mantecon said his original goal was to attract 5,000 people each Thursday through Sunday, but ended up accommodating 20,000 in each four-day weekend during the winter tourist season. He’s hosted more than 350 events for such organizations such as Nicklaus Children’s Hospital Foundation, Simon Malls and the United Way.

“We decided to take this on ourselves and make it something special,” said Mantecon, managing member of Miami-based MV Real Estate Holdings, who now plans to build space on the site for restaurants, offices, and retailers. “We accomplished what we set out for.”

The project is a South Florida-style version of efforts begun in the past two decades by developers and investors in Chicago, Los Angeles, San Diego, Washington, D.C., and other U.S. cities to turn neglected urban rivers into economic redevelopment assets, efforts that boosted land values for property owners near the waterways.

Horacio Stuart Aguirre, chairman of the Miami River Commission, said more innovative uses like the river project are needed. “This is a great lesson for commercial real estate professionals, and that’s that when God created land, he didn’t tell the earthlings what to do with it,” he said.

The 30,000-square-foot venue, with a tent and tiki huts, has attracted nearly 1 million visitors in its first year, Mantecon said.

It’s open Thursday through Sunday starting at noon, with several bars, food trucks and music and games part of the festivities. Patrons arrive on foot, by car and by boat.

During the World Cup, retired soccer star David Beckham held a watch party at Wharf Miami. Beckham is becoming a Miami celebrity after he was awarded a Major League Soccer franchise for the city earlier this year, and voters have directed city officials to negotiate a deal with Beckham to build a $1 billion privately funded soccer stadium and entertainment complex on the city-owned Melreese Country Club. Other celebrities who have visited include New England Patriots tight end Rob Gronkowski, model Tyson Beckford and actress Gabrielle Union-Wade, wife of the Miami Heat’s Dwyane Wade.

Wharf Miami and more than a dozen existing and proposed residential and commercial developments are helping revive the once-polluted Miami River.

The 5.5-mile river, which incorporates fresh and saltwater, cuts through the downtown core and flows past such neighborhoods of Overtown and Little Havana. The waterway formerly connected to the Everglades as far east as 22nd Avenue before development pushed the wetlands farther west.

A century ago, the river was the center of commerce in the city where wealthy residents chose to live, but as the downtown and suburbs developed from the 1970s to the 1990s, the river lost its appeal.

“In my opinion, it’s such a jewel,” said Mika Mattingly, a broker for Colliers International South Florida. “It’s part of the fabric of the city, and we haven’t capitalized on it or embraced it enough.”

In 1998, the Florida Legislature created the Miami River Commission to improve the waterway and the immediate area. An initial wave of development started in 2000, with the commission encouraging mixed-use projects to make the river more inviting.

Aguirre, of the river commission, said he had questions about the Wharf Miami concept but now supports the project fully. He called it an “abundantly safe” area that attracts workers and residents of nearby Brickell Avenue.

“I would not be disappointed if he prolonged the experiment beyond two years,” Aguirre said.

But Mantecon said he has bigger plans. He’s working with an architect now to design a 100,000- to 150,000-square-foot building on the site and an adjacent parcel to the south that he leases from the city. The new venture would be known as Riverside Wharf, he said.

Mantecon said he will attempt to attract best-in-class restaurant operators offering food in a variety of price ranges. He hopes to start construction in about a year, after Wharf Miami finishes its run.

Once the site’s success became apparent, he found his restaurateurs wanting to be part of the new concept, Mantecon said.

Aside from the restaurants, the building also would have other retail and offices. Southeast of Wharf Miami, another developer is planning three high-rises with residential, retail and offices that would bring even more people to the river.

“Everybody loves the proof of concept as opposed to being a pioneer,” Mantecon said. “In this particular case, we ended up being the pioneer. For us, the whole idea was to show what can be done.”