Lawrence Harris,53, will travel to the wonder of the world in May for the Great Wall Marathon 2018, with a goal of securing £2,000 for St Michaels Hospice.
It was there that his late partner, Julie Mason, received treatment after developing melanoma. 'His best friend' received 'the help that she needed' from hospice workers before her death in May, 2009.
Mr Harris said: "She was delightful and bubbly, someone who everyone liked. She was just wonderful, a one in a million person and my best friend."
"I appreciated all the care that she received, along with the after-care the family was given. They got her pain under control and cared for her during that whole time."
He added: "The challenge itself is something like 5,000 steps, I think you are given around seven hours, so I know it will be quite a difficult one. I like to push myself as far as I can go, but it is nothing compared to the pain that people in a hospice can go through. I just want to do my best to help them."
Originally starting in 1999 the Great Wall Marathon sees 2,500 runners from over 50 countries cover the 5,164 step route.
This is however not the first challenge that Mr Harris has undertaken for charity, travelling across the world and raising close to £20,000 over the years.
Among these was the Great North Run in 2008, which he ran with Ms Mason, trekking to Mount Everest Base Camp and the New York Marathon.
While wanting to support the care in the hospice the fight against cancer is a cause also close to Mr Harris's heart.
Almost 15 years ago his wife, Katherine, died of cancer at the age of 32. The pair married in 1993 and had two children together, Chelsea and James.
He said: "Katherine was a hardworking person, working as a supervisor in the Naafi (on base supermarket) when we lived in Germany and the UK while I was in the RAF. She was lively, loved life and was a fantastic mother."
To donate towards Lawrence's St Michaels's marathon fundraiser visit here