High above the bustling streets of New York City, there's a whole other world--a universe filled with calm and natural beauty. We're talking of course about New York's legendary rooftop gardens. Like their predecessors in Babylon, these urban oases truly are one of the world's great wonders. Set amid the concrete canyons, these horticultural hideaways offer respite from New York's relentless pace. High above the city that never sleeps, these serene spaces offer a chance to laze, potter and nap. The gardens' plants, furnishing, and the landscape engineering that makes them possible are sure to inspire awe. Set against dramatic cityscapes, these are some of the most fascinating green spaces on the planet.