Three days for Porto, and a fourth for the Douro valley

The port cellars are across the river in Vila Nova de Gaia

Cross the Dom Luís I bridge on the upper deck: it has the view

São Bento station's hall of 20,000 azulejos is free to walk into

Tram 1 runs along the river to Foz for €5 a ride

Eat a francesinha once, and grilled fish in Matosinhos

Where the Douro fits, and what to skip, in the full guide