If you’ve heard of New York’s extremely popular High Line (a public green space growing out of a former raised railway on Manhattan’s west side), you should be aware of its imminent foil: the LowLine, a proposed underground park on New York City’s Lower East Side. Whereas the High Line created lush and living spaces above city streets, the LowLine will bring plantings and visitors underground. The idea is a marvelous, if not exactly new one; where open space is short, people tend to put the subterranean to use. Romans buried the deceased in catacombs, and the denizens Edinburgh’s underbelly literally lived and worked in the city’s underside, in vaults under its buildings and streets. The LowLine, however, will be a lovely place to be.

The project’s leaders, James Ramsey and Dan Barasch, want to turn an unused space under Delancey Street, formerly the Williamsburg Trolley terminal, into a park. A fascinating lighting system will collect sunlight from the world aboveground and redistribute it below to chase the dank and dark away.

I had the good fortune of stumbling upon a preview of the concept a few weekends ago, which was staged to show the community what the project is all about. Guests entered a dark warehouse on Broome and Essex Streets, near the proposed location of the park. After getting through a phalanx of volunteers with clipboards and pamphlets , you met the actual project, and the sight was worth more than a thousand volunteers’ words.

A mature Japanese maple reached up into dim filtered light coming from the ceiling, and a variety of ferns and mosses covered whatever it was growing on. One couldn’t help but imagine this planting as the peak of some serene Okinawa mountain, sliced off and dropped into New York. I can’t say what the design was growing on, but it smelled of earth and compost and all those rich good things that make a garden grow. Based on first impressions, the LowLine is an innovative project to keep an eye on. If all goes as planned, you might be able to walk among plants under city streets the next time you visit New York. Visit http://thelowline.org for more information or to donate to the cause.