Underground play space [The Big Picture]

High Line Park, once an abandoned section of elevated railway on the west side of Manhattan, is now a 2.33-kilometerlong urban oasis that draws millions of visitors each year. Now a plan has been hatched to turn another out-of-use railway into a public park teeming with greenery. But this one, located on Manhattan???s Lower East Side, will grow inside an unused underground trolley terminal. If things go according to plan, the subterranean park, called the Lowline, will open in 2018. But how do you get greenery to grow in a tunnel? The park???s designers plan to use aboveground parabolic collectors to gather the sun???s rays and direct them underground. The solar technology transmits the wavelengths of light needed to support photosynthesis, letting grass grow where the sun don???t shine.