Since the early 1960s, the artists known as Christo and Jeanne-Claude have been creating unique art installations for a public that is often skeptical, sometimes welcoming, and usually completely unprepared for what they're about to experience.

The artists call their work "environmental art," because they use large pieces of fabric to highlight and set apart natural environments—urban or rural—for a short period of time. In the early 1970s, they were responsible for hanging 142,000 square feet of orange nylon fabric between the mountains on either side of Rifle Gap in Colorado. Ten years later, they surrounded two islands off the Florida coast in bright pink fabric. Other famous works include "wrapping" the German Reichstag and the Pont Neuf in France.

Each of Christo and Jeanne-Claude's projects typically requires years of logistical planning and negotiations with local governments. They demand sophisticated feats of engineering and crews numbering in the hundreds, not to mention lots and lots of the artists' own money. Their most recent project, The Gates, was 26 years in the making.

Why? What would possess anyone to create such massive (and temporary) works of art? And what purpose could they possibly serve? According to Robert Storr, professor of Modern Art at the Institute of Fine Arts in New York, "They see it in terms of making what is already in the world more visible…and visible to us in different ways. [The installations] are only part of the artwork. The other part of the artwork is the world that is already there, which we often pass by without paying any attention."

Their website confirms this perspective. "The artists temporarily use one part of the environment. In doing so, we see and perceive the whole environment with new eyes and a new consciousness."

Are Christo and Jeanne-Claude's artworks accomplishing their purpose? Listen to the testimony of Adam Cieselski and Jok Church, two men who worked on the construction crew of their California coastline project, Running Fence: "Christo said the Running Fence was a landscape with 'an obstructive membrane' in place to block and alter the view, which transforms the way people perceive it. And it did. Decades later, we can drive through Western Marin and Sonoma Counties and still find Running Fence. The landscape was untouched, unaltered, unchanged. The thing that had been changed was us."

Images of the artworks can be viewed at http://christojeanneclaude.net

Video: The Gates in Central Park