The people of Buñol, Spain, like to paint the town red. Every August, the city hosts La Tomatina, a massive food fight that involves about 22,000 people pelting each other with more than 150 tons of overripe tomatoes considered unfit for human consumption. The festival began in the 1940s, and although no one seems to know for sure what sent the first tomato airborne, one popular theory holds that teenage boys started a food fight during a parade. From there, it grew into an annual tradition, despite occasional attempts by local authorities to ban it. Today rules help keep the event from descending into complete chaos: Participants must squash tomatoes before they throw them, for example, and the fight ends after an hour, when a warning firework goes off. Then a cleaning crew hoses down the streets. La Tomatina now also includes a week’s worth of other festivities, such as musical performances, dancing, and parades, and people travel from all over to take part. “La Tomatina is not just about throwing tomatoes,” Sergio Galarza, a Buñol councilman, told reporters. “It’s about coming together and celebrating in the most outrageous way possible.”