Rambler George Mariner is taking on a charity challenge this month, inspired by his autistic grandson.

The 51-year-old has decided to trek the Inca Trail in Peru to raise cash for the National Autistic Society, after his five-year-old grandson Andrew was diagnosed with autistic spectrum disorder.

Andrew's parents have made use of the NAS helplines and now George wants to give something back by raising stacks of cash for the charity.

At its highest point, the Inca Trail is 4,200 metres - three times the height of Ben Nevis.

George, who works for Luton Borough Council's paediatric occupational therapy service, is hoping to reach a fundraising target of £3,000.

He has paid for all of his own expenses, so all donations will go directly to the charity.

Make a donation online by clicking here or send a cheque, payable to The National Autistic Society, to George Mariner at the Paediatric Occupational Therapy Service, 2nd Floor Town Hall Extension, Town Hall, Luton, LU1 2BQ.