Portugal's Douro Valley Journey

The boundary of this wine country was written into stone, and the stones are still findable. Taylor's records that the boundaries of the Port vineyard area were demarcated and marked out with 335 pillars, the marcos pombalinos. The Museu do Douro, which ran the survey that located them, dates the work in two campaigns rather than one: 201 granite markers implanted in 1758, and a further 134 in 1761. Each carried a single word cut into the granite — feitoria.

That word decided a grower's income. In 1757 the first comprehensive classification of the Port vineyards was carried out — almost a century before a similar exercise in Bordeaux. Wines classed as vinhos de feitoria could be exported and command a higher price; wines classed as vinhos de ramo were restricted to the domestic market. The pillar in the ground was the visible edge of that split, which is why a stone two metres tall was worth cutting and carting up a schist hillside.

One of the original demarcation boundaries separated the Alto Douro from the Douro Superior at the Cachão da Valeira, and the reason was geological rather than agricultural. A granite monolith in the river prevented navigation of the Douro upstream of that obstacle. Wine made above the rock could not easily be moved to Gaia, so the country above it was treated as a different place — a boundary drawn by a boat's limits.

The far bank of the river is a datable document, and UNESCO supplies the key. The earliest terrace form is the socalco, used in the pre-phylloxera era before 1860: narrow, irregular terraces buttressed by walls of schist, carrying only one or two rows of vines each and requiring continuous maintenance. They follow the contour rather than correcting it, so from a train window they read as a wandering, uneven stack of short shelves rather than as lines.

The second generation is unmistakable once the first has been seen. The long lines of continuous, regularly shaped terraces date from the end of the 19th century and the beginning of the 20th, when the Douro vineyards were rebuilt following the phylloxera attack. Regularity is the tell: a rebuilt hillside was surveyed and laid out, where a pre-1860 hillside was accumulated. The two forms often sit on the same slope, one above the other.

Density changes with the sub-region, which is why the view alters as the train runs east. Vineyard occupies about 29% of the Baixo Corgo, the western sub-region nearest Régua, and a smaller share of the two sub-regions further upriver. UNESCO's assessment calls the result an outstanding example of human ability to master physical constraints — a landscape whose builders created the soil itself and raised an immense and extensive construct of buttressed socalcos.

The boat built for that river explains the constraint. The rabelo is flat-bottomed with a shallow draught, which was necessary to navigate the often shallow, fast-flowing waters of the upper Douro before dams and locks were constructed from 1968 onwards. It is native to the Douro and exists in no other place in the world. Everything about the hull is an answer to rapids that no longer exist.

Enforcement went further than paperwork. Among the measures taken was the eradication of the elderberry tree within the demarcation — the fruit had been used to deepen the colour of thin wine, so the remedy was to remove the supply. The markers were signage as much as boundary: the granite carried the word feitoria, marking the land judged fit to produce wine for export. The IVDP, which regulates the appellation today, describes the Douro Demarcated Region as demarcated and regulated from 1756.

The railway ended the rabelo's working life, and then decorated its own station with pictures of it. In 1937 Pinhão station received the tile panels that made its name — about 3,047 tiles in 24 panels, produced at the Aleluia factory in Aveiro and installed after repair work was completed. The panels show the harvest and the river transport the trains had already replaced. Aleluia calls the result the most beautiful railway station of the Douro.