NYC’s High Line, a former freight rail line (1934–1980) that was converted to a public park, runs for about a mile and a half (2.3 km) through the Meatpacking District, Chelsea, and Hell’s Kitchen (from Gansevoort Street to West 34th, on the West Side of Manhattan). It’s public and sees millions of visitors walking the High Line a year. The first section was opened in 2009, and the second was opened in 2011.
The 23rd St. Lawn is a popular resting spot (although it’s closed on Mondays and Tuesdays for restoration). There are several kinds of tours that run fairly often, such as guided walking tours, stargazing tours, tree tours, and history tours.
For a sneak peek, watch the film I Am Legend and look for the grass-covered tracks during the hunting scene.
The High Line is open every day from 7am to 10pm. You can get there by taking subway lines A/C/E or 1/2/3 to 14th St. (8th Avenue and 7th Avenue, respectively). Visitors are not allowed to walk on the old rail tracks or over the plants (of which there are 210 species), and there is no biking or smoking on the premises.
You can read the High Line Blog for updated and more detailed information, or purchase some merchandise (like tote bags, notebooks, magnets and clothing) to support the maintenance of the High Line. There has been a proposed third section, too, but it’s not yet open to the public.