The Denver Art Museum unveiled a dramatic new piece of artwork this month [October 7]: a building. The $75 million expansion looks like a gigantic quartz crystal poking up from the ground near the state capital.

It's the first U.S. building for Polish-born architect Daniel Libeskind and proved far less controversial than his other major American project, the World Trade Center memorial. While the construction went smoothly, using the new building for art has proven exciting and exasperating.

Six years ago, during architect Daniel Libeskind's first visit to Denver, the Rocky Mountains left him awestruck. He was determined to evoke their soaring beauty in the art museum building. But he says his real muse was the people of Colorado, their expansive nature, their optimism, spirit and boldness. "[It's] the kind of boldness and the kind of power that the pioneers had who came to the Rocky Mountain region in the first place. And I can tell you that the boldness of the people here is also the boldness of the building."

Triangular shapes jut from the building, and a prow dangles over a busy downtown street. The surface is covered in puffed titanium tiles that capture the light. A glass and steel bridge, dubbed Main Street, links the 1971 medieval fortress-like building designed by Gio Ponti to the new space-age addition.

Libeskind, who created the original, winning design for the reconstructed World Trade Center site, says it's time for galleries to evolve. "We are living in the 21st century," he points out. "We are really out of the two-dimensional idea of the box and abstract architecture. Architecture is about space and it's about new possibilities. Many contemporary museums have a very interesting exterior but inside you find the same 19th century galleries that are there already for hundreds of years."

Those galleries would be perfect for displaying the museum's more traditional artwork from its Western or impressionist collections. Instead, Libeskind has given curators tilted walls, narrow corners and varying ceiling heights. Critics say it's enough to make curators want to hang themselves, instead of the art.

Associate curator Ann Daly reserved judgment when she heard that Libeskind was the architect. "I knew the museum in Berlin, which I thought was a fabulous piece of sculpture, but I knew there were difficulties there in, in installation. So I thought that we'd just wait and see." She and her colleagues participated in the design process and used large-scale models to figure out ways to display the art in the galleries.

Some artwork hovers over the floor, suspended by aircraft cables. Designers have built out vertical spaces on Libeskind's sloping walls to accommodate other pieces. Daly said the challenges of the space have forced curators to think differently, explaining, "I think it's caused people to be innovative, creative, more than the white cube would allow. So I think it has stretched all of us."

Modern and contemporary art curator Dianne Vanderlip points to a typical atypical space; not only does it tilt, it's within a meter of a sloping external wall. "You have this gigantic, intimidating, very eccentric wall. What are you going to do with it?" Vanderlip tucked a piece of neon artwork in the space. The light reflects on the opposite wall and doesn't threaten to cause light damage to nearby paintings.

The longtime curator says modern artwork shows well in Libeskind's building because the artists share his belief that the vessel for art should be as creative as the art itself. She adds that the angled walls allow for unusual pairings. "I can't think of many places where you can see the abstract expressionism on one side and at the same time be looking at pop art. And, you know ? it works."

As visitors walk up the stairs into Libeskind's Grand Atrium, they are bombarded with such contrasts. The stairs stab the space with stark white walls and black granite floors while gentle light glows through eastern facing windows. Libeskind considers this signature space the embodiment of the building's theme. The architecture grabs the eye but doesn't overwhelm the art. Museum director Lewis Sharp says some visitors have told him that has surprised and pleased them. "'You know,' [they'd say], 'I had reservations whether a building, that strong a piece of architecture, could really house the collection and present the collection in a way that was appropriate.' And every single one of them has said 'we've never been more excited by the way collections have looked. Bravo!'"

Sharp promises some encores. He says more traveling exhibits, including a show from the Louvre, are scheduled to occupy the gallery space that has ballooned 40 percent.

The building itself is expected to evolve. Daniel Libeskind says he has created not just a container or a pretty façade but a building that works. While the external walls will stay the same, museum officials expect to regularly tinker with the configurations of gallery spaces to meet the needs of the artwork displayed.