It might seem crackers but competitors from across the world will line up for one of the most odd sporting events of the year - cheese rolling.
Dozens of athletes in Gloucestershire will race each other down a steep slope in pursuit of a giant cheese.
About 5,000 spectators are expected to line the course to watch the antics of the daredevil cheese-rolling fanatics.
The winner of the chase will be rewarded with the 3.6 kg (8lb) circle of Double Gloucester cheese.
There are traditionally four downhill races, one for women, and uphill runs for children and anyone who fancies a challenge.
Cheese rolling facts
The origins of the cheese-rolling is not clear, but evidence suggests it was an old tradition by the 1850s
One theory is that the event has its roots in a pagan midsummer festival when large fires were lit at the top of hills to scare away bad spirits
The event has been cancelled three times. In 1998 because of fears over public safety, in 2001 due to the foot and mouth outbreak and in 2003 when the specialist rescue team that removes injured participants from the hill was called to an earthquake in Algeria
Because of rationing during and after the Second World War, a wooden substitute was used containing a token piece of cheese inside
But this year organisers have introduced a fifth race to the event because so many people want to take part.
In each of the races about 20 competitors run, roll and somersault headlong down the hill.
Members of the St John Ambulance volunteers will be on hand to help anyone who gets injured in the mad race.
Jim Jones, from the St John Ambulance, said: "The hill is incredibly steep and people often injure themselves falling down the hill or get hit by a flying cheese as they watch the races."
People from as far afield as America, Australia, New Zealand, Norway and Sweden travel to the hill every year to take part in the Cheese Roll.