Some of you may have seen this story  in last Friday's Real Estate section of the Times. While the High Line park will begin at Gansevoort and Washington, few people know that the High Line originally went as far south as St. John's Park Terminal, which covered four riverfront blocks between Clarkson and Spring Streets. (It's now a UPS warehouse.) In the 1960's, the High Line below Gansevoort was demolished, with the exception of the little section of rail running through the Westbeth  complex, on Washington between Bank and Bethune.
The building was originally Bell Labs, where some of the most advanced precision telecommunications instruments were developed in the first half of the twentieth century. Because trains rumbled directly through the building, its labs were fitted with sophisiticated sound-and-vibration proofing. Since the 1970s, Westbeth has been one of the city's most successful live/work communities for artists.
Since it's not contiguous with the rest of the High Line, this Westbeth portion will not be developed as part of the park, but instead remain closed to the public, (maintaining its wild, abandoned feel.) From the Times:
"25 feet above the sidewalk, the romance survives. The northerly half of the [Westbeth section], covered over by the building, is almost entirely free of plants. But the southerly part is open to the sky, and feels like an Irish heath, the ballast underneath the thin cover of plants yielding slightly underfoot. The rails are gone but rusty spikes, metal objects, a wooden tie and other leftovers attest to a time when rail was king."