It produces great wines and its landscapes are among the most arresting on the Iberian peninsula, but the Douro River Valley is no household name outside of Portugal.
The region in northern Portugal, which produces syrupy port wine from rare and prized grape varieties, celebrates its 250th anniversary today as the world's first legally demarcated wine region -- and vintners think it's time to heave the Douro's other wines into the big time.
The region has been a well-kept secret for tourists and wine-lovers for decades.
In the late summer, heavy bunches of grapes as sweet as jam dangle in vineyards that stretch dozens of kilometers down the valley. Layers of terraced vines follow the contours of the land, rippling back from the river which slices across the peninsula from Spain to the Portuguese city of Porto on the Atlantic coast.
On the giddily steep slopes of scree and powdery soil, where the midday sun makes the handbuilt slate walls too hot to touch, the stillness is broken only by the occasional distant barking of dogs and the drowsy hum of insects.
Despite its enchantment, the Douro region carries neither the glamor nor the prominence of Bordeaux, Tuscany or Spain's Rioja.
"Portugal has had problems making inroads into the international wine world. People think Portugal isn't a country that produces US$10 bottles of wine," admits Pedro Silva Reis, head of winemaker Real Companhia Velha.
Richard Mayson, a British wine expert who has written extensively about the Douro, says the key lies in changing the public perception of the region.
"It's all a question of image. It's an old problem in Portugal -- appalling marketing," Mayson said. "There's really some extremely good wine there."
Times, though, are changing. Notably, producers are developing richly textured table wines which they hope, by piggy-backing on the fame of port, will move the Douro up a peg.
"A new wave of winemakers has come through and they're trying new things. There's an ongoing revolution," Silva Reis said.
The first written references to wine from this region date from the mid-17th century.
In the 18th century the export business here boomed as England sought out alternatives to French wine, whose supply was uncertain because of trade disputes and war.
However, the success was threatened by unscrupulous producers selling lower-quality wine under fake Douro labels, so on Sept. 10, 1756 a royal charter decreed the establishment of a demarcated Douro wine region.
The charter created the Real Companhia Velha, known in Britain as the Royal Oporto Wine Company, to police the trade.
More than 300 granite pillars were placed in the soil to stake out the precious Douro.Vineyards, called quintas, were catalogued and production was logged in a pioneering scheme that would take several years to complete and would be copied around the world.
By 1799, wine from here made up more than half of Portugal's total exports.
In the mid-19th century the Real Companhia Velha switched to production and is now the Douro Valley's largest vineyard owner.
The thinly populated region is still important for Portugal. Its 43,000 hectares of vineyards produce 70 percent of Portuguese wine exports, worth 400 million euros (US$512 million) annually.
Winemaking is a way of life in Pinhao, a village at the heart of the Douro reached along sinewy roads flanked by sheer drops, about 300km from Lisbon.
"Go into a bank, a shoe shop or a butcher's around here and you'll hear people talking about wine. It's in our blood," says 34-year-old Alvaro Martinho, one of Real Companhia Velha's team of young wine experts and the third generation of his family in the trade.
More than three centuries of tradition, however, began to work against the Douro.
Reluctance to change methods handed from father to son, coupled with the fatalism of those who work the land, meant that the Douro fell out of step with trends in the global drinks market.
"There was a fear of change. The Douro forgot to modernize," Silva Reis said.
Now, Martinho and his colleagues regularly travel abroad to pick up new ideas. They are also trying out largely forgotten varieties of local grapes and new blends of table wines in their fight for more space on foreign supermarket shelves.
There are dozens of grape varieties here that can't be found in any other country: tinta barroca, tinta roriz, touriga nacional, tinto cao, rufete and bastardo.
"When we plant new vines now, we do it with a type of customer and market niche in mind," Silva Reis said. "Before, we just planted the vines and left it all in God's hands."
Tightening competition in the global drinks market after a string of international mergers and acquisitions forced producers to pull off the blinkers.
To lower production costs and keep prices down, technology is nudging aside the old ways. Mechanical grape treaders have become common. Some vineyards are using laser measurements to obtain the perfect 3 percent gradient on their vineyard terraces.
Amid the fickleness of beverage fashions, the Douro wines need to capture foreign drinkers' imagination by showing them the region's beauty, Silva Reis says.
Authorities agree and are hoping to rev up the modest local tourism industry.
At the harvest at Quinta do Vallado, local worker Francisco Maria stoops and pokes his hands into a bushy vine. He snips off a bunch of grapes and drops it into a bucket. He's been doing this since he was 11, in the 1960s, when he helped build some of the dry-stone walls hereabouts.
"People always talk about French wine and Spanish wine, but we have something very special here, too," he says.