The Old Hamm's Brewery looms over the gritty East Side of St. Paul, Minn., a redbrick citadel of suds that rolled out its last barrel in 1997 and then became a 3-hectare site for urban explorers to shoot trophy pictures and for graffiti artists to showcase their mad skillz. But beyond the busted windows and spray-painted tags, business partners Chris Ames, Fred Haberman, and David and Kristen Haider of Urban Organics see an indoor farm. Using a hybrid farming method called aquaponics,which combines aquaculture (fish farming) and hydroponics (growing plants in water), this massive, 4700-square-meter indoor field of greens will feed thousands of fish and be fertilized by the resulting fish poop. Nothing will go to waste.