NEW YORK - Ever since the High Line was unveiled in 2005, the design for this park, conceived for a strip of elevated rail tracks abandoned nearly 30 years ago, has been the favorite cause of New York’s rich and powerful. Celebrities attended fundraisers on its deck. City officials endorsed it. Developers salivated over it, knowing it would raise land values.

I worried that it would one day be overrun with tourists and film crews. How, I wondered, could it possibly retain the tranquillity that made walking along its rusting, decrepit deck such a haunting experience? So I was overjoyed recently when I climbed the stairs at Gansevoort Street on Manhattan’s Lower West Side, entered the new city park and felt an immediate sense of calm. Designed by James Corner Field Operations with Diller Scofidio & Renfro, the first phase of the High Line, which opened in early June, is a series of low scruffy gardens, punctuated by a fountain and a few quiet lounge areas, that unfold in a lyrical narrative and seem to float above the noise and congestion below. It is one of the most thoughtful, sensitively designed public spaces built in New York in years.

But what’s really unexpected about the park is the degree to which it alters your perspective on the city. Guiding you through a landscape of derelict buildings, narrow urban canyons and river views, it allows you to make entirely new visual connections between different parts of Manhattan while maintaining a remarkably intimate relationship with the surrounding streets.

The park currently extends as far north as West 20th Street. A subtle play between contemporary and historical design, industrial decay and natural beauty sets the tone. The surface of the deck, for example, is made of concrete planks meant to echo the linearity of the old tracks. The path slips left and right as it advances, so that at some points you are right up against the edge of the railing and at others you are enveloped in the gardens. And those gardens have a wild, ragged look.

What saves all this from becoming a saccharine exercise in nostalgia is the sophistication with which these elements are fused together. The benches, for example, have a sleek, contemporary feel.

But as mesmerizing as the design is, it is the height of the High Line that makes it so magical, and that has such a profound effect on how you view the city. Lifted just three stories above the ground, you are suddenly able to perceive, with remarkable clarity, aspects of the city’s character you would never glean from an office window.

Longer views open up down narrow side streets to the Hudson, or east across the city.

At the same time, you are still close enough to make eye contact with people on the sidewalks, so that you never lose your connection to the street life. The High Line is the only place in New York where you can have this experience - one that is as singular in its way as standing on the observation deck of the Empire State Building.