But in the last two decades, the Douro's storied winemakers have gradually turned their attention from port to table wines, using indigenous grapes like touriga nacional, a rich, heat-loving fruit that they believe has the potential to make world-class red wine. (So do respected wine critics like Jancis Robinson.)

Wine-seeking visitors usually stay near the small towns of Peso da Régua and Pinhão along the Douro River. Until recently, that usually meant two options: charming but rustic bed-and-breakfasts like the Casa do Visconde de Chanceleiros, an 18th-century manor about three miles outside Pinhão; and the Vintage House Hotel, the area's grandest hotel, where the bartenders open port bottles the traditional way: heating and snapping off the necks.

This summer, the region saw the arrival of two modern boutique hotels, which are drawing a younger, more cosmopolitan breed of travelers to the region. The Aquapura, a chic Asian-inspired hotel designed by the Portuguese architect Luís Rebelo de Andrade, opened with 50 bedrooms including 9 suites, 21 villas with burgundy plunge pools, and a 23,600-square-foot (almost a 1-square-meter) spa.

And the place that has everyone talking is the Quinta da Romaneira, which was transformed into a luxurious resort on 990 acres of terraced hills covered in vines. It has 20 suites and apartments, a riverside spa and an eye-popping all-inclusive rate of 1,000 euros (about $1,470) a night for two, which includes meals, private cooking lessons and chauffeured wine tours.

But perhaps the surest sign of the Douro's rising status is the rush of chef-driven restaurants. For Redondo, its upscale restaurant, Romaneira brought in two renowned cooks to create the menu: Philippe Conticini, formerly of Petrossian in Paris, and Miguel Castro e Silva, one of Portugal's most respected chefs.

In Peso da Régua, the culinary buzz is at Douro In, a riverside restaurant with old stone walls, modern Philippe Starck furniture and an inventive menu that blends Portuguese fare with global styles. And in between Régua and Pinhão, there's the excellent DOC, the latest outpost from Rui Paula, whose first restaurant, Cêpa Torta in Alijó, has been a favorite of the Douro's wine producers for more than a decade.

On another evening, at the remote Casas do Coro, a hotel spread throughout what once was a medieval village, I encountered yet another of the Douro's unexpected surprises. The hotel's modern restaurant — with gleaming wood surfaces and theatrical lighting — served a traditional meal of mirandesa (veal from the region) cooked by the owner's talented wife. Both the surroundings and the food captured the essence of the new Douro — a destination stepping toward the future, with one foot firmly in its rich, earthy past.

Still, the meal I remembered most was the spontaneous dinner at Quinta de Nápoles. Maybe that's because for several days after I returned home my feet were still purple.