For the past two summers, a different giant artwork has appeared on the plaza adjacent to the Minneapolis Convention Center downtown. Get ready for a third to make its debut at Northern Spark June 13, as the Creative City Challenge finalists have been chosen. Each will get a stipend of $2,500 to present a final proposal in February to a panel representing the city, the convention center and northernlights.mn, the arts organization behind all-night-long arts extravaganza Northern Spark. The winner gets $75,000 to create their temporary dream, which will remain available to visitors through the season.

"Shadow Swings" (computer-generated model pictured above) a concept by a team from the architecture firm Perkins+Will, combines a series of wind-chime-outfitted swings under a canopy. Each has a different musical tone, encouraging visitors to make up a song together.

"We All Share the Same Skies" (above) by the design firm PLAAD offers outdoors-related sensory experiences -- wind through pines, images of constellations and clouds, simulated downpours -- in three separate enclosed structures, bringing a bit of the north woods to an urban setting.

For "Mini_Polis," (above) artists Niko Kubota and Jon Reynolds will erect plywood miniatures of buildings in Minneapolis' downtown and environs, rigged interactively to share the memories of and hopes for these places expressed by their makers, groups of volunteers in community workshops.