Each country has its iconic celebration. In France, it's fireworks over the Eiffel Tower. In Italy, it's a crazy horse race. And in Spain, it's bullfighting. Next on our party tour: the biggest bull festival of all, Pamplona's Running of the Bulls.

Officially known as the Festival of San Fermín, the Running of the Bulls is perhaps Europe's greatest adrenaline festival. For nine days each July, throngs of visitors — most dressed in the traditional white, with red sashes and kerchiefs — come to run with the bulls…and a whole lot more.

The festival, which packs the city, has deep roots. For centuries the people of this region have honored St. Fermín, their patron saint, with processions and parties. He was decapitated in the second century for his faith, and the red bandanas you see everywhere are a distant reminder of his martyrdom. And you know, I don't think anyone on this square knows…or even cares.

But at the Church of San Fermín, it's a capacity crowd…and there's no question what to wear for this Mass. To this day, locals look to Fermín, their hometown saint, for protection.

Back out on the streets, it's a party for young and old. There's plenty of fun for kids. And towering giants add a playful mystique to the festivities.

The literary giant, Ernest Hemingway, is celebrated by Pamplona as if he were a native son.

Hemingway first came here for the 1923 Running of the Bulls. Inspired by the spectacle, he later wrote his bullfighting classic The Sun Also Rises. He said he enjoyed seeing two wild animals running together: one on two legs, and the other on four.

Hemingway put Pamplona on the world map. When he first visited, it was a dusty town of 30,000 with an obscure bullfighting festival. Now, a million people a year come here for one of the world's great parties.

After dark, the town erupts into a rollicking party scene. While the craziness rages day and night, the city's well organized and, even with all the alcohol, it feels in control, and things go smoothly. Amazingly, in just a few hours, this same street will host a very different spectacle.

The Running of the Bulls takes place early each morning. Spectators claim a vantage point at the crack of dawn. Early in the morning? Nope — for many of these revelers, it's the end of a long night.

The anticipation itself is thrilling. Security crews sweep those not running out of the way. Shop windows and doors are boarded up. Fencing is set up to keep the bulls on course and protect the crowd.

The runners are called "mozos." While many are just finishing up a night of drinking, others train for the event. They take the ritual seriously, and run every year.

At 8:00, a rocket is fired, and the mozos take off. Moments later, a second rocket means the bulls have been released. They stampede half a mile through the town from their pens to the bullfighting arena. At full gallop, it goes by fast.

Bulls thunder through the entire route in just two and a half minutes. The mozos try to run in front of the bulls for as long as possible — usually just a few seconds — before diving out of the way. They say on a good run you feel the breath of the bull on the back of your legs.

Cruel as this all seems for the bulls — who scramble for footing on the cobblestones as they rush toward their doom in the bullring — the human participants don't come out unscathed. Each year, dozens of people are gored or trampled. Over the last century, 15 mozos have been killed at the event.

After it's done, people gather for breakfast and review the highlights on TV. All day long, local channels replay that morning's spectacle.

The festival's energy courses through the city. Overlooking the main square, the venerable Café Iruña pulses with music and dance. While the masses fill the streets, VIPs fill the city's ballrooms — it seems everyone is caught up in this Festival of San Fermín.