Why 'blindness is a gift' for inspirational athlete
He's flown between continents running seven marathons in a week and plunged into the sea at Alcatraz three months after learning to swim.
Dave Heeley, known as Blind Dave to family and friends, gradually lost his sight throughout adulthood.
But it spurred him on to attempt ever more extreme challenges and he's raised millions of pounds for charity.
Now aged 60, Dave, from West Bromwich, in the West Midlands, is planning a Great Wall of China trek as his next adventure.
Video journalist: John Bray