La Tomatina in Valencia, Spain

Everywhere I turn, people are battening down the hatches or tacking polythene sheets to storefronts to protect them from La Tomatina's carnage. The old men and women of Buñol line up chairs along the narrow streets that lead into the square. Adults and children clutch buckets of water on the balconies above, ready to pour over the baying mob gathering around me. What have I let myself in for?

Welcome to Buñol. This industrial town 40km (25 miles) from Valencia is preparing, as it does every year, for La Tomatina and I am one of tens of thousands of people from around the world who have found their way here -- swelling its population of 9,000 to 40,000 -- to pelt total strangers with tomatoes for one crazy hour.

La Tomatina began around 1945, and although no one can be certain as to how the festival started, various theories abound, from two friends having a heated argument over dinner that turned into a food-tossing brawl, to class wars and the messy aftermath of a lorry spillage. One thing is certain: the festival has turned into an event of international renown.

At around 10am, the action begins as trucks begin to trundle through the town, transporting some 100 tons of tomatoes from Extremadura into Plaza del Pueblo. At the same time, some of the bravest members of the crowd are clambering to the top of a greased-up pole to reach a strategically placed ham. Once this much-coveted prize is claimed, water cannons fire, the trucks empty their load and the battle begins.

Within moments I am enveloped by a riot of semi-clad bodies covered head to toe in acidic, vitamin C rich, red gunge. It is hard to contain my excitement as I crush handfuls of tomatoes to lob at the person next to me (not before checking that they are smaller and weaker -- I don't want to aggravate the local bruiser). Consumed by the mass of men and women running riot and ripping off shirts, I fling caution to the wind and lunge after my next victim. The smell is overpowering, and I am soon wondering if I can ever look at a pizza the same again.

After exactly one hour, the water cannons fire again and the fight is over. While the firemen hose down the town and its willing victims, I clean myself off, still dazed by the thrill of taking part in a food fight the likes of which can't be found even in the pages of a St. Trinian's novel.

When: Last Wednesday of August. Activities kick off around 10am; the fight does not start until the ham is claimed and this can often take a long time.

Don't miss: A trip to the river to wash off (being washed by firehose is not a fun experience).

About the crowd: Protect yourself with goggles and boots (for girls, sports bras are also recommended). And don't wear white.

Insider tip: Wear proper shoes and not sandals -- stubbed toes aplenty occur thanks to the tomato sludge that envelops the town.

What else?: Like so many other events in Spain, La Tomatina was banned under Franco, and reinstated on his death.

Get there: Buñol is around 40km (25 miles) west of Valencia with its international airport.

Price: Free.

Information: (tel. +34 963 606 353; www.latomatina.org)