Douro Valley

From the river or from the narrow roads that hairpin up the valley sides, the scale of the Douro Valley is at first almost disorienting. The river is far below — a silver thread between walls of vine-covered schist that rise hundreds of metres on both sides — and the terraces that make this landscape possible are human constructions stacked against hillsides that would be bare rock everywhere else in Europe. The socalcos, as the stone-walled terraces are called, were built without mortar using dry-stone techniques that have changed little since the Romans first brought viticulture to this region, and they require constant maintenance to survive the winter rains.

The wine terraces are maintained entirely by hand: the schist walls are built without mortar and are prone to collapse after heavy rain, the soil behind them is brought up from the valley floor in baskets, and the vines are pruned and harvested by the same families that have worked these plots for generations. This is a manual agriculture that has survived the 20th century's wholesale mechanisation of European viticulture because it cannot be mechanised — the terraces are too steep and the schist too unstable for machinery. The result is a wine-growing landscape that is also a feat of civil engineering maintained by human labour at a scale that is breathtaking.

The quintas (wine estates) that line the valley are as much architecture as agriculture. The weathered schist walls of the terrace faces are the dominant landscape element; the estate houses come next — whitewashed buildings with arched port wine lodges where the wine matures in large wooden vats — and below them the river itself where the rabelo boats were once moored, loaded with barrels for the journey down to the lodges in Vila Nova de Gaia. This complete system — terraced hillside, quinta, river — is visible today more or less as it was in the 18th century.

The Alto Douro Vinhateiro (Upper Douro Wine Landscape) was inscribed as a UNESCO World Heritage Site in 2001, making it the first wine region in the world to receive the designation — recognition of a cultural landscape that is also a functioning agricultural system, not a preserved museum or heritage theme park. The inscription was awarded for the combination of the physical landscape (the terraced hillsides, the schist geology, the river corridor) and the cultural practices (the wine-making traditions, the quintas, the seasonal rhythms of harvest and pruning) that together constitute the Douro wine culture.

October is harvest time in the Douro Valley. The vine leaves turn yellow and the terraces fill with pickers — many of them casual seasonal workers from Porto and the surrounding Douro villages — and the quintas press the grapes in the same stone lagares (open-topped granite fermentation tanks) that were used before mechanisation, though some estates now use a combination of traditional and modern stainless steel presses. The wine that results from this ancient landscape — the port wine that is the Douro's most famous product — is unlike anything else: a fortified wine of extraordinary complexity that has been produced here for three centuries.

The schist geology of the Douro Valley is fundamental to the character of port wine. The poor, thin soil forces the vine roots deep into the fractured schist in search of water and minerals, and the heat stored in the dark stone overnight extends the growing season and ripens the grapes fully even at these northerly latitudes. The schist also provides excellent drainage, preventing the vine roots from sitting in water during the wet winters and ensuring the stress conditions that concentrate the sugars and tannins in the grapes. The geology and the wine are inseparable.

This is the oldest regulated wine region in the world, formally delimited in 1756 under the Marquês de Pombal, and the Alto Douro Vinhateiro was the world's first UNESCO-listed wine cultural landscape — a recognition that the Douro Valley is both a natural and a cultural achievement.

The human achievement encoded in the terraced valley walls is on a scale with any built monument in Europe: centuries of manual labour have transformed hillsides that would otherwise be bare rock into one of the world's finest wine-producing landscapes, and the terraces themselves are feats of dry-stone engineering.

The Douro Valley is best experienced slowly, from the river or from the road that follows the north bank — the N-222 between Pinhão and Régua is widely considered one of the great drives of Europe, with the vine terraces and the river visible together at every hairpin bend.