Porto, verdict by verdict

Porto is the doubter's favorite Portuguese city: a granite-and-tile riverfront stacked on a gorge, port lodges across the water in Gaia pouring aged tawnies, the Clerigos tower's 360-degree roofscape, the six-bridges river cruise sliding under Dom Luis I, and a working centre that never fully polished itself for visitors. The food, wine and views outrun the prices, and even the Livraria Lello's famous staircase is worth the ticket when the crowds behave.

The caveat is vertical: Porto is one long hill, so steep climbs and cobbles come with the territory, and Atlantic rain can show up in any week of the year, not just winter. The Ribeira waterfront is the most touristed, overpriced strip in town, Lello packs shoulder-to-shoulder at peak hours, the Douro valley day is a glorious 12-hour commitment, and the metro stops around 00:45 so late arrivals need a car.

Two to three days covers the centre, Ribeira and a Gaia tasting afternoon; add one for the Douro terraces around Pinhao or Guimaraes' medieval core. Sleep up in Baixa and walk down rather than up, come May to October for river evenings with June adding the Sao Joao street party, and treat the port cellars as one good guided tour rather than two.