The Running of the Bulls, known as encierro in Spanish, is a tradition during which people run in front of a group of young bulls running through the streets. At the end of the run, the bulls are corralled in preparation for bull fighting. The best-known encierro takes place in Pamplona, Spain, and typically lasts a little less than four minutes.
More on the Running of the Bulls:
From 1910 to 2012, there were 15 deaths during the Pamplona encierro.
In addition to the the encierro in Pamplona, there are several other bull runs in Spain and Portugal, and even one in Mesquite, Nevada, in the United States.
Some animal rights groups, including People for the Ethical Treatment of Animals (PETA), oppose the Running of the Bulls on the grounds that the run and bullfight constitute animal cruelty.