The Ribeira is Porto's ancient waterfront and its most photogenic neighbourhood — the row of tall, narrow houses cascading down to the Douro quayside, their tiled and plastered facades in various states of grandeur and collapse, is the image that most people carry away from the city. It is a real neighbourhood as well as a scenic backdrop: the narrow alleys behind the quay are full of washing lines, barking dogs, and restaurants catering to both tourists and locals.
The Cais itself runs along the river below the Ponte de Dom Luís I, with café tables spilling onto the pavement and small boats tied up at the stone quay. In the evening it is where Porto gathers to drink wine, eat grilled fish, and watch the light change on the water. The tourist presence is heavy, but the setting is genuine, and the best approach is simply to eat here once, walk along the river, and then explore the streets above. The Escadas do Codeçal — a long staircase cutting up from the quay — leads through medieval lanes to the cathedral plateau above.