What do you do with an abandoned trolley station? Build a massive underground park!

That’s exactly what Dan Barasch wants to do. New York City has two-thirds the green space per resident as other big cities, but converting the Williamsburg Bridge Trolley Terminal into a park the size of a football field would create a respite from the bustling streets. By redirecting sunlight from the roads above, it is possible to illuminate a luscious community space below, nicknamed the Lowline for its similarity to Manhattan’s beloved High Line.

Watch Dan's talk to see renderings of the park and the science behind his prototype »