Poble Sec sits in the narrow strip between the Paral·lel and the Montjuïc hillside, and it has always been a working neighbourhood that knew how to enjoy itself. Three kilometres in the evening, from the old music-hall avenue to a street built for grazing, with a Civil War shelter and three brick chimneys in between.
Start on the Avinguda del Paral·lel, once the city's avenue of cabarets and still wide enough to feel the ghost of them. Head for Les Tres Xemeneies — the trio of 72-metre stacks left from La Canadenca, the power station that first electrified Barcelona, now presiding over a graffiti-covered skate park. From there it's a short climb to Refugi 307, the air-raid shelter the neighbourhood dug into the hill by hand; it opens for tours on set days, so check first.
Then the reward: Carrer de Blai, a pedestrian run of bars where you eat pintxos off cocktail sticks and pay by the count. Wander the quiet streets above to let it settle, then drop back to Poble Sec metro on Line 3, the chimneys lit behind you.
