Every year at the end of September, Barcelona braces itself for La Merce: the end-of-summer party that bids 'adios' to the summer and says 'hello' to the fall. It’s one of the city's biggest fiestas with people flocking in from around the country to relish in the free concerts, street art, human pyramids and innovative exhibits that take place day and night for four days straight.

Held in honor of Mare de Deur De La Merce, the Patron Saint of Barcelona, the festival is one of the year's most exciting, fun and enjoyable parties. And, its free concerts only make it that much more appealing to locals, foreigners and travelers alike.

La Merce — Photo courtesy of La Merce

If you're looking for a list of events, just look for signs all over the city saying LA MERCE 2012. They give you a detailed schedule of what's going on around town, including the concert times, venues and live shows, such as the acrobats and fire masters. 

It's definitely worth it to try and plan your evening if you have your heart set on one particular concert, as the plazas get busy and it can feel like you're trying to navigate your way through a mosh pit.

La Merce Concert — Photo courtesy of Concerts la Merce

Plaza Sant Jaume in particular, is always packed as is Plaza Espanya and Plaza Felipe Neri in the Gothic Quarter. And if you have kids, there are plenty of wonderful options to keep them entertained during the day, so be sure to get a brochure and check out the list of scheduled activities.