Week long fiestas which take place in Pamplona.
From July 7th onwards crowds of people take to the streets drinking, dancing & singing.
Early in the morning bulls are released along the narrow streets which lead to the bullring and people risk serious injury by running in front of them - a custom which is also typical in many Spanish villages.
Semana Santa
Easter. This is a very important holiday in Spain and involves spectacular processions with members of cofradías (brotherhoods) dressed in hooded robes and carrying their pasos (religious floats or statues) through the streets.