Cheese rolling is a rather mad annual event in Gloucestershire that routinely sends a significant number of entrants to hospital (33 out of 50 in one year). The premise is simple: 15 people at a time chase a round, three-kilogram cheese down a very, very steep hill, and the winner keeps the cheese.
No one is sure how or why cheese rolling got started, or even why it continues, but it has been going on for at least 400 years. This chronically unsafe activity has also damaged spectators over the years, with several requiring treatment after being hit by a 100 km/h cheese.