These pyrotechnicians stage an annual fireworks war where they erect barricades in a park, hide behind them, and then fire roman candles and other fireworks at one another.
Every year two teams come head to head on a battlefield complete with bunkers and boundary lines and face off in a full-scale pyrotechnics battle that has lasted up to 4 hours or more.
Each year, months before the battle, the participants design and construct weaponry and armor to improve the quality and quantity of "ammunition" they can fire at the opposing team. Any size/type of fireworks you can afford is fair game, with a few guidelines set in place so we don't literally blow each other to bits… completely.
(Thanks, Stuart!)

Update: Rachel sez, "in Taiwan, there's a town where, every year for the Lantern Festival, they turn the center of the town into, well, a battlefield of fireworks. A motorcycle helmet, full body coverage and a nice dousing with water is de rigeur for attendants. The officials explode a huge amount of fireworks, *really close* to people, and lots of the people attending aren't too careful about where they aim. Mike Rogero, also has a very nice selection of images from the Yanshui festival."
