If you travel several kilometres out from Porto's centre, you enter siesta-still neighbourhoods that only come alive towards sundown. On our first evening in the city, we crossed Luís I Bridge and entered Vila Nova de Gaia. From this side of the river, you could see the city spill across the hillside, houses shining red, yellow and blue as tiles reflected the softening light. We walked for a while along the water's edge, passing derelict warehouses that trailed ivy.
As we turned the corner towards the Douro's mouth, the murmur of tourists fell away, and we reached São Pedro da Afurada, a traditional fishing village occupying a handful of cobbled streets. Here the rows of houses stood bright in dappled sunlight and shadows cut across coloured tiles in sharp shapes. The streets were sleepy and near-silent. Washing hung on pink pegs and locals sat by their doorways in plastic chairs.
When we reached Taberna São Pedro, the restaurant was just setting up. Chefs stoked red-hot coals and placed skewers of calamari on the outside grills. Soon the air was filled with smoke and the smell of barbecued fish. We sat outside, sipping cold beer and picking apart the shrimp shells with increasingly sticky fingers.
Come morning, we walked in the same direction on the opposite side of the river, tracing a coastal boardwalk next to the waves of the ferocious North Atlantic. At points, we stopped for beer and padron peppers and sat facing the spray, eyes dazzled by a cloudless sky.
Eventually, we arrived at Matosinhos, a major fishing port and beach that's home to many traditional seafood restaurants. Here, Rua Heróis de França is so full of charcoal-burning grills that the smoke stings your eyes and clings to your clothes. We stopped to watch the men flip and prong the seared skin of crisping sardines before finding a free roadside table on which we tried the local delicacy. These fish - thin, spider-web bones and head still attached - are best eaten with a side of buttery, boiled potatoes.
Not all of the best cuisine is situated outside the city centre, however. Traipsing along Porto's charming maze of streets, we found lively restaurants serving francesinha - a sandwich stacked with ham, sausage, steak and cheese, and covered in a beer-and-tomato sauce. You can opt for a fried egg on top and chips on the side. We tried this traditional Portuguese dish in Cervejaria Brasão Aliados, and it proved great fuel for strolling up and down the city's many hills.