Largest nude sledging world championships

Germany's annual Braunlage Nackt Rodeln Weltmeisterschaft or Nude Sledging World Championships were founded in 2009, and in 2012 attracted around 400 entrants (of whom only 30 qualified for participation) and 25,000 spectators. Competitors must strip down to their underpants and sledge down a 90-m-long (295-ft) ice piste in the Harz mountains, although they are allowed a helmet for protection. For the most recent event (February 2012), the spectators outnumbered locals by five to one, prompting organizers to cancel the 2013 competition owing to concerns about health and safety.