A Cattelan Billboard for the High Line After his blockbuster retrospective at the Guggenheim Museum in New York last fall, Maurizio Cattelan, who is just 51, said he was officially retiring from making art. What did that mean, exactly, coming from a jokester like Mr. Cattelan? One answer comes in the form of a billboard, 75 by 25 feet, at 10th Avenue and West 18th Street in Chelsea, next to the High Line. It is a giant image of a woman's 10 perfectly manicured and jeweled fingers, detached from their hands, emerging from a vibrant blue velvet background. It was unveiled on Thursday and can be seen from both the elevated pathway and the street. The billboard is part of a High Line series that began last December with "The First $100,000 I Ever Made," a blown-up photograph of a real $100,000 bill, the largest denomination the United States government ever printed, by the Los Angeles artist John Baldessari. This new billboard - the fourth - will be on view through June 30. Mr. Cattelan created the image with the photographer Pierpaolo Ferrari as part of Toilet Paper, a two-year-old art magazine founded by the two men. But what about Mr. Cattelan's supposed retirement? "It's not like it's my own," he said, laughing, about the billboard. We worked together. He explained that he is "in between moments," adding, "I'm missing it, but it's good to have distance." The billboard's photograph was taken in Milan, and while Mr. Cattelan and Mr. Pierpaolo held casting sessions to find just the pair of hands to shoot, Mr. Cattelan said they happened on an old woman in a bar near the sessions and asked her to pose. "It's like a magic trick," said Cecilia Alemani, director of the public art program at Friends of the High Line. It's almost cinematic in its format. Mr. Cattelan called the image "Surreal but verging on Pop," adding that "it's a bit gory but without the blood." But why show just those fingers and not the rest of the hand? "Fingers are something sexual, like penises," he explained. It doesn't always have to be a cigar. The art world begins decamping to Europe later this month for Documenta 13, the huge show of contemporary art held in Kassel, Germany, every five years; for Art Basel in Switzerland; and for a round of important Impressionist, Modern and contemporary-art auctions in London. Add one more draw. In Arles, in the south of France, a Roman amphitheater has been filled with 80 truckloads of sand, and from July 5 to July 8 there will be an evolving exhibition called "To the Moon Via the Beach," by a group of 20 international artists including Pierre Huyghe, Rirkrit Tiravanija, Lawrence Weiner and Daniel Buren. Over the course of four days, the amphitheater will be transformed from a beach to a moonscape, with interventions from the artists and a team of sand sculptors led by Wilfred Stijger. "It's one enormous experiment," said Tom Eccles, director of the Center for Curatorial Studies at Bard College in Annandale-on-Hudson, N.Y. Mr. Eccles is part of a group of artistic advisers that includes the artists Liam Gillick and Philippe Parreno and museum directors like Hans Ulrich Obrist, co-director of the Serpentine Gallery in London, and Beatrix Ruf, director of the Kunsthalle, in Zurich. The team was assembled by the Luma Foundation, led by the philanthropist Maja Hoffmann, as part of a major initiative to transform Arles into an art city. The foundation has commissioned the Los Angeles architect Frank Gehry to design a cultural complex for Arles, but until that is completed, it is using different sites: This year the amphitheater is its outdoor studio. "This is the first major, large-scale example of what will become the foundation's ongoing artistic program in Arles," Mr. Eccles said. On June 19 three sculptures by Ellsworth Kelly - one in bronze, another in mahogany and a third in redwood - will occupy the soaring glass atrium of the Morgan Library & Museum, where they will be on view through Sept. "They are totems," Mr. Kelly, who turned 89 on Thursday, said in a telephone interview. Each one is heavy at the top and smaller on the bottom. He explained that when he was choosing the sculptures from his studio in Spencertown, N.Y., only works that could stand on their own were eligible; none of his much-loved wall pieces would work in the Morgan's atrium. And, "I wanted each to be of a different material," he said. This is the third summer for contemporary art in the atrium. Last year "The Living Word," a floating, iridescent cloud of Chinese calligraphy by the Conceptual artist Xu Bing, was on view. Before that were three steel sculptures by Mark di Suvero. In addition to Mr. Kelly's sculptures there will be studies, models and drawings that illustrate his working methods and his thinking. "This is an institution dedicated to the creative process," said William M. Griswold, director of the Morgan. Acquisitions that get attention at the Museum of Modern Art tend to be works by brand-name artists whose output is scarce and expensive. But a recent gift of 13 double-sided drawings by Henry Darger, the American outsider artist, underscores the breadth of the museum's permanent collection. Unrecognized in his lifetime, Darger, who died in 1973, tended to use popular images from comics and magazines and materials photographically manipulated at his local drugstore. "Darger was one of those standout, self-taught artists who has had an enormous influence on many generations of younger artists," said Connie Butler, MoMA's chief curator of drawings. And we have had a long history of collecting so-called outsider material, which is a lesser-known piece of MoMA's history. While the American Folk Art Museum has significant holdings by Darger, this gift, from the artist's estate, is MoMA's largest acquisition of work by an outsider artist. Klaus Biesenbach, the director of MoMA PS1 and MoMA's chief curator at large, organized "Disasters of War: Francisco de Goya, Henry Darger, Jake and Dinos Chapman" at PS1 and was instrumental in the acquisition.