In less than a decade, Manhattan’s High Line has gone from urban eyesore to cause célèbre. The 1 1/2-mile stretch of long-abandoned elevated rail line, winding 22 blocks amid (and sometimes through) gritty warehouses and by glittering new condos from western midtown to the Meatpacking District, was set for demolition in the late 1990’s—until famous neighbors (Diane von Furstenberg, Edward Norton) rallied around an initiative to transform the railway bed into a visionary “floating park” two stories above street level (thehighline.org). Designed by cutting-edge architects Diller Scofidio + Renfro and landscape architects Field Operations, the $170 million project’s first phase (from the High Line’s southern terminus at Gansevoort Street to West 20th Street) opens by year’s end. Staircases, elevators, and ramps will lead to an aerial parkland filled with walkways, benches, and plantings.