Architects Tadao Ando and Annabelle Selldorf reinvent the Clark Art Institute, in the Berkshires.

How do you turn a museum inside out? That was the question the Clark Art Institute, in Williamstown, Massachusetts, asked as it embarked on a major expansion, to be unveiled this month. The Clark always had an awkward relationship with its surroundings: the original museum—a Neoclassical white-marble temple built in 1955—turned its gaze inward, ignoring the bucolic sweep of its 140-acre setting in the Berkshire Hills. Enter Tadao Ando, the Pritzker Prize–winning Japanese architect acclaimed for his boldly austere buildings suffused with poetic plays of light. His reimagination of the entire Clark campus makes the landscape fully part of the experience.

Visitors now arrive at a serene, glass-walled pavilion set along a broad terrace, which overlooks a one-acre, three-tiered reflecting pool. “The architecture pays respect to the existing buildings and encourages people to connect with nature,” Ando says. The two-level space accommodates special exhibitions, a café, and a shop; Ando also designed a lustrous, glass-sheathed portico that serves as a new front door for the original museum.

That existing building was expanded and overhauled by architect Annabelle Selldorf, known for Manhattan’s Neue Galerie. Her redesign of the Clark shifts the focus to the art. Galleries that once encircled the skylit central hall have been reconfigured so that visitors “experience them as rooms, not as a racecourse,” Selldorf says. Other upgrades include energy-efficient lighting and reproportioned galleries—the better to enjoy the institute’s permanent collection of French Impressionists (Renoir; Degas) and 19th-century American painters such as Homer, Inness, and Sargent.

The Clark reopens July 4 with three exhibitions: ancient Chinese bronzes (on view through Sept. 21), Abstract Expressionism (on view through Oct. 13), and David Smith’s 1962 Circles sculptures (on view through Oct. 19).