A city of northwest Portugal near the mouth of the Douro River north of Lisbon.

波尔图葡萄牙西北部一城市，位于里斯本北部，杜罗河口附近。

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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

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