A man from Orpington is attempting to break a world record in a triathlon event only 34 people have ever managed to achieve.
Chris Leek is undergoing the infamous Enduroman Arch 2 Arc event, starting underneath Marble Arch he'll run 87 miles to Dover, swim across the English Channel then cycle to the end at the to the Arc de Triomphe in Paris.
To hold the record he'll need to finish in under 73 hours.
The challenge is all to raise money to help tackle dementia in honour of his father who suffers from the disease.
You can sponsor Chris here.