La Mercè is Barcelona's largest annual festival, held each year in late September in honor of the city's patron saint, and it fills the city center with free public events for several days.
What to expect
Signature elements include correfoc ("fire run") processions with costumed devils and fireworks, human towers (castells) built by local teams competing in the city's main square, and a giants' parade featuring oversized painted figures that have been part of Catalan festival tradition for generations.
It's free and citywide
Unlike a ticketed festival, most La Mercè events are free and spread across multiple neighborhoods and squares, with a published schedule released closer to the date each year.
Plan around the crowds
Central areas like Plaça de Sant Jaume and Plaça Espanya get very busy during headline events, so arriving early for a good vantage point — or watching from a slightly less central location — makes for a more comfortable experience.
