To fully experience the Douro Valley, however, head upstream to the Alto Douro (Upper Douro) wine region.

BBC: The changing landscape of the Douro River Valley

Set in a restored relic that overlooks the Douro, the eight rooms at Guest House Douro have gorgeous wooden floors, queen beds and marble baths.

BBC: Mini guide to Porto and the Douro, Portugal

One of the Douro Boys, a group of winemakers that drove this change, welcomes visitors for table wine tastings at Quinta do Crasto.

BBC: The changing landscape of the Douro River Valley

Warehouses emblazoned with company names that recall British and other foreign founders line the south bank of the Douro River, and most have guided tours and tastings.

BBC: The changing landscape of the Douro River Valley

The Portuguese director Manoel de Oliveira, a centenarian, reaches to the world beyond for this story of mad love and self-consuming art, set in the rustic realms of the Douro wine country.

NEWYORKER: The Strange Case of Angelica

Although all Port, produced in the Douro River Valley of Portugal, is made the same way (partially fermented wine is fortified with a neutral spirit, which stops fermentation and raises the alcohol level), there are two distinct types: ruby and tawny.

WSJ: Why You Should Make Time (and Place) for Port | On Wine by Lettie Teague