Although the official public holiday falls on the 24th, Saint John's Day, the real celebrations take place on Saint John's Eve, what Catalans call 'la revetlla' - the evening before an important festival, where the concept of evening is stretched until the early hours of the following morning. Now we've covered the basics, it's time to sketch a plan for some midsummer madness. Start the night with a glass of cava and an aperitif: you'll need plenty of energy if you're going to survive until morning.
You'll also need strong nerves: unsupervised kids with bags of noisy firecrackers are part and parcel of the tradition. Pretty soon the whole city is vibrating to the sound of ricocheting bangers. This could be a good moment for a slice of coca - the colourful candied fruit, glace cherries, scattered pine nuts and liberal dusting of sugar make an edible firework display in themselves. A strong coffee and you're ready to join the party.
One of the best ways to experience the festival is to join one of the street parties held in Barcelona's different districts - there are over 50 in total. Some offer tickets that include a sit-down supper, drinks, coca de Sant Joan and concerts, while others simply provide tables and chairs so that people can bring their own party out onto the street.
As well as the information on its website, the Ajuntament has created a downloadable smartphone app that provides all the practical information you'll need to enjoy the festival. If all the different ways of celebrating Sant Joan have a common denominator, it's the inclusive nature of the festivities: it's a festival for everyone to enjoy in the open air, on one of the first nights of summer.
There are already more than quite a few, the faithful patrons of Bar Calders, and surely they will not miss the Sant Joan party the bar is putting on. The night starts with a tapas-based dinner, home-made by Ramon and company, which costs €25 and it's essential that you book in advance. An alternative is to go through the passageway on C/Parlament from 11pm, to sip a glass of cava and move your feet to some funk and Brazilian tunes.
The neighbours who live in and around C/Aldana are in the mood for a party, with fireworks and bangers and the lot. So Jonny Aldana, Bar Olimpia and Los Juanele have joined forces and, while still shining in their own individual ways, they'll celebrate Sant Joan together in a united front.
Revetlla de l'Eixample Esquerre
Barcelona's Colectivo Gay will take over Passatge de Valeri Serra and convert it into a Sant Joan party with all the trimmings (that is, there won't be any shortage of garlands). Following the Triangle and Pink Brick awards and the big dinner, the 'festa al karrer' street party kicks off with DJ Ivankof and drinks with prices that'll put a smile on your face. And if it's a bonfire you're after, at the crossroads of Consell de Cent and Borrell, you'll find one lit up by the neighbourhood association.
Revetlla de la Barceloneta
For those who want to see the sun come up with their toes in the sand, one of the best options is planning your party among the bonfires of Barceloneta. The party starts early, at 9pm in the Plaça de la Barceloneta, with a big drum party and 'la nit del foc'; starting from midnight you'll get your dose of music to dance to till dawn.