The High Line is a linear park made from the remnants of an elevated freight rail line that ran from the Meat Packing District on the West Side of lower Manhattan all the way up to midtown. The first segment of the park just opened to the public and goes from Gansevoort Street up to about 20th Street. Currently you have to enter the park (as seen below) from the Gansevoort Street entrance. Eventually the park will go up to 33rd Street.
For decades the rail line was unused and ever decaying. As if humans needed a reminder that we are superfluous to life on this planet, it also proved to be a repository for all kinds of wild flora eager to take back this thin slice of Earth. Any seed with even a little bit of moxie managed to find fertile soil on the tracks turning the abandoned line into an urban meadow. The truly wild meadow is no longer there, but the park designers, and the great Dutch landscape architect Piet Oudolf did an amazing job recreating a space that manages to maintain the wild spirit of the High Line.