It's a food fight that sees over a hundred tons of overripe tomatoes being thrown around. Every year, on the last Wednesday of August, tens of thousands of people take to the streets of the Spanish town of Buñol, armed only with tomatoes, which they then throw at each other.
It's called La Tomatina, and the celebrations last for a week, featuring music, parades, dancing, fireworks and plenty of good food.
In fact the night before the battle of the tomatoes, participants compete in a cooking contest to see how they can make the best paella (a rice dish originating from the Valencia region of Spain, where La Tomatina is also celebrated).
No one is sure when the festival began, though many estimate that it has been around for at least 60 years.
Today, thousands of tourists descend on the small town of Buñol. The town's population is normally 9,000 and, by some estimates, up to 40,000 tourists turn up each year to take part in La Tomatina.
The days before the festival, as the town celebrates in preparation for the tomato fight, local shopkeepers cover their storefronts with plastic sheets to prevent damage. Participants in the tomato fight are also urged to wear safety goggles and gloves, for safety reasons.
When the momentous occasion arrives, and once the town's water cannons are fired, it's every man for himself as the city's streets are flooded with tomato pulp. The only rule, other than the requisite goggles and gloves, is that everyone must squish their tomato before throwing them at anyone. Additionally, no one is allowed to throw anything other than tomatoes, of course.
An hour later, the water cannons are fired a second time -- to signal an end to the fighting.
Once the fighting has stopped, fire trucks take to the streets, cleaning the last vestiges of the tomato war.
La Tomatina is ostensibly in honor of Buñol's patron saints, Luis Bertran and the Mare de Deu dels Desemparats (Mother of God of the Defenseless, another name for the Virgin Mary).
In an interesting historical side-note, Spain's Gen. Francisco Franco banned the festival during his dictatorship for its supposed lack of religious significance.
But, perhaps proving that you can't keep a good food fight down, the festival made a triumphant comeback after Franco's death in the 1970s.
Theories abound as far as La Tomatina's mysterious origins are concerned -- from a local food fight between pals, to an accident involving a ton of tomatoes falling off a truck. There is no dearth of stories regarding its background.
One of the most popular notions is to do with angry locals throwing tomatoes at town officials. However La Tomatina came to pass, it is now a staple part of the Buñol calendar and a must-see for tourists going to Valencia during August.
And, although some bloggers have criticized the festival for wasting food at a time when so many nations are battling food shortages, there seems to be no end to its popularity.