From Akron, Ohio, to St. Paul, Minnesota, entrepreneurs, activists and designers are quietly collaborating on ways to reimagine the places where they live and work. The Knight Foundation’s Cities Challenge rewards these innovators.

One group wants to host communal dinners for city residents; another wants to create a park under an old railway. For the second year, the foundation has awarded grants to projects that are devoted to improving their communities.

Related: Most innovative cities in America

This year, 37 projects from 19 cities won a total of $5 million. But the scope of the projects was even greater: More than 4,500 groups submitted their takes on innovation (from the 26 cities where the Knight brothers used to own newspapers). Here are a few of the winning projects:

The Metrorail, which runs on an elevated track in Miami-Dade County, is 26 miles long. The space underneath most of is unused. Meg Daly’s vision is to transform 10 miles of it into an urban park called The Underline.
“It would be the only linear park in the country that’s connected to a mass transit system,” she said. The transformation is necessary for the community, said Daly. “Miami-Dade County is the fourth most dangerous in the country for pedestrians and the most dangerous place in the state for bicyclists,” she said. “The infrastructure isn’t there to safely allow these activities.” The Underline would include pedestrian and bike paths and 100 acres of open space with gardens, open air gyms, dog parks and play areas for kids. Daly, through her Friends of the Underline nonprofit, has already raised $7 million for the project, which she estimates will cost $80 million overall. The initiative received $250,000 from The Knight Foundation, which will fund an outdoor gym. “A lot of young people live here. A public urban amenity like this will attract more young talent because it will improve their quality of life,” she said. “But it will take a village to get it done.”