On a crisp fall evening a clutch of bigwig museum directors were barefoot and treading grapes in an old stone vat in the Douro, Portugal's port wine region. They included João Fernandes, the director of the prestigious Serralves Museum in Oporto, and Vicente Todoli, the director of Tate Modern.

These days, however, this rugged valley is on the edge of becoming a fashionable wine trail. There are more than a few signs: a group of renegade winemakers who called themselves the Douro Boys; new luxury hotels with 1,000-euro-a-night suites; restaurants with Michelin-starred chefs; and new wineries designed by famous architects.

But unlike other, well-traveled wine regions, much of the Douro's intoxicating charms sneak up on you. I had come to Quinta de Nápoles, a 74-acre vineyard on an isolated hilltop overlooking the Tedo River, to taste its red wine made from the grapes of old port vines. Luís Seabra, the resident winemaker, led a small group of us on a tour among the barrels, pulling out batches from various vintages to taste.

The next thing we knew, Dirk van der Niepoort, an owner of the vineyard, joined our small group, fielding questions about the grape-growing climate and excitedly telling us about Quinta de Nápoles's new winemaking facility, a minimalist complex made of stone, designed by the Austrian architect Andreas Burghardt and completed this fall.

After regaling us with stories about the Douro's history, Niepoort spontaneously invited us to a dinner with Fernandes and his art friends. We sat comfortably around a long wood table as the family chef brought out plate after plate of earthy Portuguese fare: a big salad with juicy local tomatoes, followed by buttery potatoes and an enormous platter of cabrito (a roasted young goat) with sweet onions and carrots. And, of course, some of the vineyard's top labels were served: Charme 2004 and the Redoma Branco Reserva 2005.

"There's 2,000 years of winemaking history in the Douro," said Niepoort, a fifth-generation heir of the family-owned port company, Niepoort. "But it's only in the last 15 years that the wines are becoming good and in the last five that they've become outstanding."

Much of that outstanding wine is being made by five small wine producers who recently formed a winemaking clique called the Douro Boys. These "boys" ( Niepoort is one) range in ages from the early 30s to mid-60s — and one is a woman.

What binds them is an "obsession with quality, an ambition to bring our wines to international markets and a belief in sharing and helping each other to make that happen," said one of the older of the Douro Boys, Guilherme Álvares Ribeiro of Quinta do Vallado.

Another common denominator is that all of the Douro Boys are descended from, or have worked for, the region's old port-making families. The Douro Valley, which stretches almost 100 miles from the Serra do Marão mountains toward the Spanish border, was designated a wine appellation in 1756, making it one of the world's oldest.