"Parks in large cities are usually thought of as refuges, as islands of green amid seas of concrete and steel. When you approach the High Line in the Chelsea neighborhood on the lower west side of Manhattan, what you see first is the kind of thing urban parks were created to get away from—a harsh, heavy, black steel structure supporting an elevated rail line that once brought freight cars right into factories and warehouses and that looks, at least from a distance, more like an abandoned relic than an urban oasis."
This is the beginning of the great article by Paul Goldberger that you can read here.
And you can also "visit" the High Line thanks to this time-lapse video by photographers Diane Cook and Len Jenshel, and senior producer Hans Weise.
Images and text from National Geographic.
Lots of information, images, videos... at the High Line official web site.