Yes: Porto is worth three days, and four with the Douro valley

The Dom Luís I bridge: one view up high, one at water level

Milder summers: August highs of 24.8°C, against 28.8°C in Lisbon

The slope disappoints: from the Ribeira to the cathedral is a climb

Least worth it October to March: every month above 95 mm of rain

Skip Lello if the queue is long; the tiled church fronts are free

Who Porto suits, and who should skip it, in the full guide