Courtesy of Castellers de Cerdanyola
All the summer´s other festivals were just dress rehearsals for this one as Barcelona sees out the summer with Festival la Mercè - a tribute to the Patron Saint of Barcelona, Mare de Deu de la Mercè.
Wherever you are in the city, it'll be hard to miss. If you're new in town, look out for the correfoc (literally, running with fire) as fire-throwing devils aim to scare the bejesus out of you. If that sounds like your thing, make yourself as unflammable as possible by wear long sleeves and nothing too loose.The route traditionally takes in Plaça Sant Jaume which is also the site of the castellers, the uniquely Catalan tradition of building human towers. Gegants - larger than life models of kings and queens that can't miss a good parade - are another fixed feature of the festival. There's also concerts, exhibitions, parades and much more. Best of all, it's free. For full details of the line-up, check the website (although sadly the information is only up in Catalan for now).
One final note, don't forget your umbrella. It traditionally chucks it down with rain during La Merce which some claim to be the tears of Barcelona's other forgotten patron saint, Santa Eulalia. Bless her.