The fiestas are celebrated in honor of Saint Fermin, patron of Navarra, and both the religious elements and the wild partying elements live out the fiestas in good harmony. There are even people who manage to attend to both sides of the fiestas without any problem.
The rave-up basically consists in the consumption of large quantities of alcoholic beverages (and/or the consumption of other light - but illegal- doses) and music and then whatever energetic response each individual wishes to add. It's as simple as that. Perhaps one of the most surprising things about the Sanfermin Festival is the abscence of hassle or rows, considering the amount of alcohol that is being consumed. There are rarely if ever any rows or disturbances of any kind. On the other hand, accidents are not infrequent what with all the mayhem going on. Enjoy yourself and let the rest of the people doing the same. That is the gold rule. The alcoholic rave-up is mainly concentrated in the old part of town, although there are other scenes, somewhat quieter and less hectic, going on in some of the other parts of town. During Sanfermin you can go everywhere to have a drink with your friends, cause everything is mixed up. The rest of the year there are different scenes with their distinctive character, so it will depend on your tastes.
Sanfermin is internationally known for the event of the running of the bulls, where the bulls are let loose through some of the streets of the old part of the city. The runnings of the bulls take place from the 7th of July to the 14th of July inclusive at 8.00 am in the morning. At midday on the 6th of July the fiestas open with the txupinazo rocket. That day there is no running of the bulls but there sure is a lot of partying.