Tucked amid the hills of Napa’s Stags Leap District, a small winery that broke ground more than a decade ago is drawing international attention — and many visitors to Carl Doumani’s Quixote winery are as interested in the place itself as in winemaker Mario Monticelli’s elegantly powerful petite syrahs and cabernets.

Small wonder: Quixote’s wines are outstanding, but the building is like no other winery in the world.

The only structure in America designed by the eccentric and whimsical Viennese artist Friedensreich Hundertwasser (1928-2000), it’s all bright colors and undulating lines, appearing to blossom from the base of the Stags Leap palisades.

Hundertwasser aficionados will find all the hallmarks of his exuberantly organic style at Quixote: No two windows are the same and straight lines are nowhere to be found. Bright, natural light is everywhere. Olive trees grow on the roof; blue tiling trickles in rivulets down the outside walls.

From his desk beneath a golden onion dome, Doumani can enjoy his visitors’ wonderstruck expressions as they walk up the path toward his door.

“By the time they hit here, they’re smiling, and that’s what we want,” Doumani said. “If they walk in here and they’re happy, they’re going to like our wines more.”

It’s hard to imagine a grumpy mood in Quixote’s light-filled tasting room, an uneven ellipse that’s half windows, its floor tiled with end-cuts of walnut and oak.

One curving wall displays what Doumani calls his “rogue’s gallery” of photographic portraits: family members, a young Sidney Greenstreet, Buster Keaton with an elephant, “the only known picture of Picasso being nice to a woman” and other curiosities.

A patio garden and wall mosaic beckon visitors outside, where Hundertwasser used blue tiles to “drip” from the roofline in a nod to Quixote’s nearby reservoir.

The tiles, like many of Hundertwasser’s materials, are often cracked or broken and always irregularly shaped.

“His philosophy is: Straight lines are anathema,” Doumani said. “No two windows are alike, no two doors are alike — that would be boring.”

That concept took some explaining to the craftsmen charged with realizing Hundertwasser’s design: They had to be convinced that tile should be laid haphazardly and that plaster should not be smooth.

In turn, the workers were invited to make their own suggestions as the winery took shape. On visits to the site — which was under construction for much of the 1990s — Hundertwasser consulted with the masons and builders and often incorporated their suggestions into his design. One example: A boulder seat in the shape of a giant mushroom.

“That was part of his genius, bringing the people working on the building into the process, asking their advice,” Doumani said. “Lots of times he took their advice.”

Hundertwasser also took a saw to the parapet to make sure the roofline was suitably uneven, and — to make a point — a hammer to an already-installed ceramic column that had been made to order in Germany.

“He said, ‘They won’t know that you use things that are broken unless they see it,’” Doumani recalled. “You never throw anything away. That would be wasteful.”

Trees on the roof

Unlike wine country palaces that seem designed to call attention to themselves, Quixote nestles into its surroundings with surprising subtlety. The sharp-eyed passing on Silverado Trail can catch a glimpse of the onion dome — which reflects the light in different colors depending on the time of day — but Doumani has taken pains to veil his Hundertwasser as the designer himself intended, with mature olive trees screening the colorful building and even growing on the roof.

“You leave the building so it looks much as it did before from the air,” Doumani explained: hence the roof garden, with more than two feet of soil, which is now being replanted after the repair of leaks that had plagued the first installation.

Up close, the building reveals itself against its backing palisades like an invitingly pleasant hallucination.

“We were looking for something that was fun and colorful and witty,” said Doumani, who stumbled across Hundertwasser’s work in a calendar.

“I think that wine and the drinking of wine and eating is a social thing, and it’s fun, and I think that the building that it’s made in and where we work making it should be fun.”

Doumani, who founded Stags’ Leap Winery before starting Quixote in the late 1980s, made contact with the artist through Smithsonian curator Harry Rand “who, fortunately, likes Stags’ Leap wine,” and furnished a letter of introduction.

The winemaker and the designer — each known as a bit of an iconoclast in his field — began a years-long collaboration on the Quixote project, the final cost of which Doumani says today he doesn’t know.

“We didn’t keep track, otherwise we might not have done it,” he said.

At Quixote, Hundertwasser’s art isn’t limited to the building and its surfaces; there are also prints on the wall and a Rosenthal ceramic dish on the tasting-room table.

Hundertwasser even designed the label for Doumani’s flagship Quixote petite syrah, a festival of colors — some reflective — that seem to twinkle in the light. Take this bottle to a restaurant, and all eyes will be on your table — such is the appeal of even the smallest work by Hundertwasser, whose adopted name means “liberty kingdom hundred waters,” and who believed in the power of the golden dome.

“It’s very important to him,” said Doumani, who often speaks of the late designer in the present tense. “He just says it makes things better.

“Your life will change and good things will happen when you work under the gold-leaf onion dome.”

Quixote offers tours and sit-down tastings for $25 a person by appointment only; the winery can accommodate up to eight visitors three times a day, “and fun is had by all,” said General Manager Lew Price, dubbed “the Revel Rouser” by Doumani.

Call 944-2659 or e-mail lew@quixotewinery.com to make an appointment.