From Kickstarter, the online platform that transforms design concepts into consumer products, comes an idea for transforming an abandoned underground trolley terminal in Manhattan into the nation’s first underground green space. And while it won’t be the first underground park in the world-that honor may lie with Shanghai-it will be the first underground recreational space in the U.S. (commercial space first prize goes to Kansas City, Mo).

Given the population density of Manhattan, and the difficulty finding existing housing, it’s not surprising that someone would want to take the fun underground. After all, there is a New York High Line-a complete park built on a repurposed elevated rail line. Why not a Low Line?