A visitor takes in Anri Sala's Ravel Ravel Unravel installation in the French pavilion of the 55th Venice Biennale. Gabriel Bouys/AFP/Getty Images hide caption

itoggle caption Gabriel Bouys/AFP/Getty Images

Visitors explore Robert Irwin's Scrim Veil--Black Rectangle--Natural Light during its 2013 reprise at the Whitney Museum of American Art. ©Robert Irwin/Photography ©2013 Philipp Scholz Rittermann/Courtesy of the Whitney Museum hide caption

itoggle caption ©Robert Irwin/Photography ©2013 Philipp Scholz Rittermann/Courtesy of the Whitney Museum