WILLIAMSTOWN, Mass. — Early in the evening Saturday, Pritzker prize-winning Japanese architect Tadao Ando climbed a trail in the woods with red lanterns and chimes hanging from tree branches, crane and koi fish puppets dancing above him, and the country air filled with the sounds of a Japanese drum troupe.

A few hundred others followed, making their way to the opening party for Mr. Ando's building, the Stone Hill Center, at the Sterling and Francine Clark Art Institute in Williamstown, Mass.

"This is a chapel in a hill, a place where you find a purpose," Mr. Ando said, looking at his glass- and wood-clad structure housing galleries, meeting rooms, and the Williamstown Art Conservation Center.

For conservators, the facilities are a dream, offering natural light by which to work, and perfectly framed vistas out their windows. In the galleries, natural light streamed in from full walls of glass on paintings by Winslow and Homer.

The Clark has long taken art and nature as its theme. The windows of the original galleries look out on a lush lily pond, and a system of trails are the site of year-round exercise and recreation.

The Stone Hill Center is now a focal point en route to a cow pasture and the top of Stone Hill, where visitors can admire the gables and chimneys of a classic, well-preserved New England town, and the grand buildings of Williams College.

Approaching from the trail — with the parking lot hidden — the Stone Hill Center looked more like the avant-garde second home of art collectors than a museum expansion.

"It does have a domestic feel to it. The quality of the site and the architecture make the function of the building somewhat recede," the director of the Clark, Michael Conforti, said.

At the party were many of the people involved in the building of the Stone Hill Center, such as Kulapat Yantrasast, Leif Selkregg, and Gary Hilderbrand (who is also designing landscapes for the Parrish Art Museum and Crystal Bridges Museum of American Art), as well as the architects who are designing the Clark's presence at MASS MoCA, Dan Wood and Amale Andraos, whose work is on view this summer at P.S.1.

Also in attendance: the collector and philanthropist Emily Pulitzer, who hired Mr. Ando to build the Pulitzer Foundation for the Arts in St. Louis; artist Ellsworth Kelly; the Cooper-Hewitt's curatorial director, Cara McCarty; the director of the J. Paul Getty Trust, James Wood; the director of the Institute of Museum and Library Services, Anne-Imelda Radice; the vice chancellor for New York University Abu Dhabi, Mariët Westermann; the retired intramurals director at Williams College, Renzie Lamb; the owner of Blantyre, a luxury inn and spa in Lenox, Mass., Ann Brown, and several of the Clark's New York patrons, such as Susan Baker and Michael Lynch, Aso Tavitian, and Katherine and Frank Martucci. The Martuccis are the sponsors of a new exhibit on the main campus, "Like Breath on Glass: Whistler, Innes, and the Art of Painting Softly."

The Berkshire hills are alive with art this summer. The director of the Tony Award-winning production "In the Heights," Thomas Kail, is directing the world premiere of "Broke-ology" at the Williamstown Theatre Festival, and at MASS MoCA, 60 painters are creating 100 of Sol LeWitt's wall drawings for an exhibit opening on November 16.

agordon@nysun.com