Artists Christo and Jeanne-Claude told delegates from around the world who toured “The Gates” yesterday that they want people to think of their projects as a once-in-a-lifetime experience.

“We love these words: Once upon a time there was `The Gates’ in Central Park. Once in a lifetime and never again,” Jeanne-Claude said at a reception for “sister city” delegates at the Boathouse in Central Park.

She said the aesthetic quality flowing through “The Gates” and their other projects is “love and tenderness,” borne out of the works’ temporary nature.

About 100 delegates from Beijing, Budapest, Cairo, Jerusalem, Johannesburg, London, Madrid, Rome, Santo Domingo, and Tokyo made the trip as part of the Sister City Program of the City of New York. Their two-day trip also included a visit to the newly expanded Museum of Modern Art on Friday. They appeared to be charmed by Christo and Jeanne-Claude, whom they peppered with questions during the reception after taking a walk through “The Gates.”

The 16-day public art installation, which ends February 27, features 7,500 gates of saffron-colored fabric swaying in the breeze along 23 miles of the park’s footpaths.

“It creates a space for your imagination. It really does look like a river of light,” said one delegate, Johannesburg’s director of arts and culture, Steven Sacks. “It interacts with you.”

The artists are known for their works including surrounding 11 islands in Miami with pink fabric in 1982; wrapping silver fabric around the German Reichstag in 1995; and opening 3,100 umbrellas in Japan and California in 1991.