Where/when: Osaka, Japan: September

Unbelievably unsafe in theory and practice, the Danjiri Festival takes drunken locals and makes them surf on the roof of tall, wobbly vehicles. Since 1703, the towns-folk have designed elaborate floats and, on September 15th, they race them around Osaka's ancient roads and narrow streets. Year-upon-year, bones get smashed as rickety floats topple and overly-competitive racers come to blows.

Freakiness factor: High - Although this is meant to be fun, fatalities are a common occurrence.