Ribeira and the Luís I Bridge

The Ribeira is where Porto began and where nearly every visit ends up, again and again. The old riverside district runs along the Cais da Ribeira, a cobbled quay lined with narrow, many-windowed houses painted ochre, rust and blue, their balconies hung with washing and their ground floors given over to tascas and terraces. Behind it, stairways and alleys climb steeply toward the cathedral through what UNESCO inscribed in 1996 as the Historic Centre of Oporto, a listing that explicitly includes the Luís I Bridge and the Monastery of Serra do Pilar on the Gaia bank. The bridge is the star. Opened in 1886 and designed by Théophile Seyrig, a former partner of Gustave Eiffel, it is a single wrought-iron arch carrying two decks: the lower one at quay level, used by pedestrians and local traffic between the Ribeira and the port lodges of Vila Nova de Gaia, and the upper one high above the river, where the metro glides across beside a broad pedestrian walkway. Walking both decks is the classic Porto loop. Cross low from the Ribeira to the Gaia waterfront for the view back at the stacked old town, then climb, by stairs, by the Gaia cable car, or by the funicular on the Porto side, to the upper deck and the Serra do Pilar terrace for the panorama that sells the city. Rabelo boats, the flat-bottomed craft that once carried wine barrels down from the Douro Valley, are moored along both banks. It costs nothing, it is open at all hours, and it is at its most magical in the last hour of daylight, when the facades glow and the river turns gold.

The history explains the look. This was Porto's merchant waterfront for centuries, a place of quays, warehouses and fish markets crammed between the river and the medieval walls, and its houses grew upward because there was nowhere else to go. Fire, floods and the rise of Gaia's wine trade all shaped it, and the Praça da Ribeira, the little square at its heart, has been rebuilt more than once. Before the iron bridges, the river was crossed on a bridge of boats, which collapsed under a crowd fleeing French troops in 1809 in one of the city's great tragedies; a bronze plaque on the quay remembers the victims. The Luís I Bridge replaced an earlier suspension bridge on the same line, and its two decks, the upper one aligned with the hilltop cathedral district and the lower with the quay, solved Porto's oldest problem of a city split between high ground and riverbank.

Working the visit: start high and finish low, or the reverse, but do both decks. A good loop begins at the cathedral terrace, drops down the stairways of the Barredo quarter to the Ribeira, crosses the lower deck to Gaia for the lodges and the view back, then rises to the Serra do Pilar viewpoint, the best panorama in the city, before returning across the upper deck as the lights come on. The upper walkway is wide but exposed, with the metro passing close by, so hold onto small children and hats on windy days. The quay restaurants are scenic and mostly aimed at visitors; for better value walk a street or two back, or cross to the Gaia side, where the terraces face the old town and the sunset.

When to go and what to avoid: early morning is quiet and photographers have the quay to themselves; late afternoon into sunset is the busiest and the most beautiful. In summer, and above all on the night of São João in June, the riverfront is packed and the bridge is part of the party. Watch your footing on the polished cobbles in rain, keep an eye on pockets in crowds, and ignore the touts selling boat trips at the water's edge until you have compared them with a pre-booked cruise. Everything else in old Porto, from the Palácio da Bolsa to the port lodges, is a short walk from here, so most first-timers cross this river several times a day without trying.