On a sculpted mound of grass overlooking the Schuylkill River, the late-day sun casts shadows from a mass of black rock. They sidle down the mound with autumnal solar grace, the lengthy type of shadows that signify the end of summer. Maybe sculptor Isamu Noguchi intended to accentuate shadows with his black rock: there are four others in the new Sculpture Garden at the Philadelphia Museum of Art.

The Sculpture Garden opened earlier this month, atop a 442-space parking garage that serves the museum, the nearby Water Works restaurant, and other area institutions.

"The Sculpture Garden allows the museum to expand its gallery space into a natural setting . . . [that's] a work of landscape art in itself," Timothy Rub, chief executive officer of the Art Museum, said in a news release.

Visitors emerge from the parking garage in a glass pavilion at the entrance to the garden. Behind this pavilion is a winding path from the Upper Lawn, which runs along a wall made from rocks unearthed during the building process. The other side of the path has a variety of botanicals, and overlooks stepped garage ventilation and Kelly Drive. The garage was lauded for its natural ventilation system by the Environmental Protection Agency, and the metallic grating has a contour itself.

So far, the space seems to be getting positive reviews from those who stop by to take in the view.

"I think it's a good way to use the space on the top of the garage," said Fairmount resident T.J. Ginieczki, who visited the garden with his family last week. "I like how it's landscaped: it's minimal, and a continuation of what Fairmount Park looks like around the museum."

At the bottom of the main path is a landing with stairs down to the larger promenade outside the museum and Kelly Drive. Another set of stairs loops back up to the upper terrace and the start of the winding path. In all, the garden encompasses an acre of space.

"I think it's wonderful," said Joe Huddy, another neighbor. "I think I've never seen a more beautiful roof, plus at some points in this garden it's quieter because of the structure. It keeps away the River Drive noise."

Lyne Raymond has been an Art Museum member for 23 years - she joined when she was a student and hasn't missed a year since. "I think the upper terrace is my favorite because of the Noguchi," said Raymond. "We'd love to see more sculptures. I like the scale, there are some low ones and high ones where you can see children could really love it."

For now, the Art Museum Sculpture Garden is an evolving space that will change with the seasons. Lighting throughout the garden could allow for a pleasant evening stroll, and the landscape will certainly change with the coming seasons.

"It looks like it's started to be a very beautiful garden and it will grow better and better as the greenery grows and more sculptures are added," Raymond said.

At the least, he said, the Sculpture Garden is a unique way to turn necessary expansion into a navigable canvas for years to come.**