New York City has its share of famous parks, but they don't pepper the landscape like they do in other big cities. The non-profit group Lowline may have a technical solution to that lack of greenery, however. It just crowdfunded preliminary work on an underground Manhattan park whose solar technology will fill an abandoned trolley station with natural, plant-sustaining light. The key is a collector that concentrates light above the sidewalk, funnels it through irrigation-like tubes and distributes it through domes. Provided the test run (Lowline Lab) works out, New Yorkers will have a 1-acre safe haven from urban chaos just underneath the Lower East Side -- it might even stay green all year round.