July 6 to July 14 (Pamplona, Spain)
Every year from July 6 through 14, hundreds of thousands of revelers, dancing to traditional pipe bands, pack into the center of Pamplona to kick off Spain's most famous bull-running fiesta in honor of the Navarre capital's patron saint, San Fermin. Spain stages more than 3,000 fiestas a year--everything from fire walking to goat-throwing--but nine days of partying and running with the bulls at Pamplona still triumphs in terms of spectacle and recklessness.
Soon after daybreak on July 7, brave runners (some might say stupid runners) dash ahead of fighting bulls as they run 825 meters (half a mile) between the corral where the bulls are kept to the bull ring where they will be killed by matadors later in the day. Runners aim to feel the breath of the bulls on their backs, and some even goad the animals by swatting them with rolled up newspapers--all while trying to avoid being gored or trampled.
The San Fermin festival is reported to have began in 1591 when its purpose was purely practical, to move the bulls to the arena. The difference was that then only a handful of daring souls ran the gauntlet in front of the frenzied beasts. The tradition was immortalized in Ernest Hemingway's novel The Sun Also Rises in 1926, after which time many more foreigners began attending the festival and running with the bulls.