It looks like a glimpse of a delicate fantasy world, this majestic tree rooted in an unseen soil and shrouded in a rose and azure diaphanous mist that teasingly peeks out to lure the curious and the harried.

Upon closer inspection this dream world expands into an orchard with smaller trees layered with the soft pastels.

This shimmering peaceful world exists as a large new impressionistic mural painted on the side of a three-story building in the middle of the 700 block of Eighth Street SE, across from the Marine Barracks and in the midst of trendy Capitol Hill storefronts.

It is the newest addition to the city's mural landscape, and its fragile quality, reminiscent of an exquisite Oriental work, is a sharp departure from its more exact and detailed cousins that include the Metro Canyon mural downtown and the portrait of Marilyn Monroe on Connecticut Avenue just above Calvert Street.

"One man came up to me while I was painting and said, 'Aren't you afraid the first strong wind is going to come and blow that thing away?' " recalled Patricia Cooney, 27, a Dupont Circle artist who painted the mural. "He thought I was using chalk pastels [instead of latex paints]. He didn't expect something so soft and painterly on a wall."

The mural, which was completed three weeks ago, is located in Kelly's Alley, a tribute to its patron Margo Kelly. Kelly, a Capitol Hill resident and real estate entrepreneur, had been thinking for months about how to decorate the wall of the building she owns at 729 Eighth St. SE.

"Instead of having a scrawl of graffiti there, I thought it would be nice to have something pretty, worthwhile and pleasant on the wall," said Kelly, 60, who came to the United States in 1950 from Dusseldorf, Germany, as a diplomat with the West German Embassy. Since leaving the foreign service and settling on Capitol Hill, Kelly has gone into business buying and renovating buildings along Eighth Street.

Kelly remembers the Eighth Street of 20 years ago as "a bowery."

"In those days Eighth Street was mostly pawn shops, liquor stores and a lousy bar called The Ship's Cafe," she said. "I used to walk around the area and think: This is really a magnificent street with beautiful buildings and tremendous facades. How nice it would be to see this area grow."

Kelly visualized the mural as "something light and breezy, whimsical and childlike, along the lines of Chagall and Manet," and Cooney's style seemed to fit that description.

Cooney, an art school graduate, spent several years living in an old warehouse loft in Boston waiting tables at night and painting during the day. For her, the mural was a dream come true.

"There I was, coming from being a harried office worker, and suddenly I had this beautiful opportunity to do nothing but paint," said Cooney, a slender woman with long brown hair who usually dresses in black. "I would wake up in the morning and my most pressing thought would be: Do I want to work with the pinks today or with the blues?

"It took me a while to adjust," Cooney said. "Mural painting was a new experience for me: I had to learn to deal with the wall. As an oil painter, I was used to working on a canvas. On a wall the dimensions are completely different. Everything had to be transcribed from the oil sketch to fit the dimensions of the wall."

To reach the second and third stories, she used a safety belt tied to the roof and climbed a 40-foot ladder.

And there were the sidewalk art critics. "Every day, people would stop to talk and ask how the work was going," Cooney said. "I got a lot of feedback from people, especially from the women in the community."

Among those who live and work around Eighth Street, reaction to the mural has been varied, ranging from tacit approval to enthusiastic support.

"It's different," said Gina Lyons, office manager of the Washington Dental Health Care Clinic at 729 Eighth St., on the northern side of which the mural is painted.

"I haven't really had time to look at it," Lyons said, "but some of our patients have commented on it. They all think it's very pretty."

Bill Boyd, owner of El Mercado, an interior design store across the alley from the mural, said, "I think it's fabulous. We could use more works of art in this neighborhood."

Raenelle Zapata, office manager for the Advisory Neighborhood Commission for Southeast Capitol Hill, said, "We haven't received any negative comments from the neighborhood, so if the community is enjoying the mural, then that's all well and good."

Three weeks ago the mural was officially dedicated by Kelly, Cooney and supporters in a ceremony held nearby. A small plaque with the inscription "Kelly's Alley" was placed on the wall by the street entrance.

"I hope that people will be enjoying this mural 10 years from now," Kelly said. "I hope it will always add something to the beauty of the neighborhood."