Solo, Mercat de Sant Antoni works.
Come on a Sunday morning and lead with the fair: the long-running 'Mercat Dominical de Sant Antoni' wraps the building with stalls of secondhand books, vintage comics, stamps, coins and old magazines, and it's a genuine local institution, not a tourist set-piece. The rest of the week it's a beautifully restored 1882 iron-frame market (reopened 2018) for fresh food, ringed by the streets that have become the city's hottest vermouth-and-brunch zone. The catch: it's a working neighbourhood market, not a Boqueria-style eat-as-you-go food court, so come for the Sunday fair, the produce and the surrounding bars rather than a sit-down market feast.