Roman port at the mouth of the Douro, Portus Cale gave Portugal its name. A city of merchants and sailors, Porto was shipping wine from the Douro valleys by the 18th century, aged in the cellars of Vila Nova de Gaia across the river.
The 19th century left its iron bridges, including the Dom Luís Bridge, and its azulejo-covered churches. Its historic centre, a World Heritage Site since 1996, keeps its narrow, colourful houses, vintage trams and a simple hospitality built around northern Portuguese food.