A determined Brent Council officer trekked 26 miles up and down three peaks of Yorkshire to raise money for charity.
John Shankar, an older people services manager, completed the marathon climb in just 12 hours, despite bad weather, some wrong turns and accidents along the way.
Mr Shankar, who was one of two team lead-ers guiding 30 other walkers, has been training for the fundraising event for nearly three months.
He said: "The training was nothing like the real thing.
"In Yorkshire we had to climb peaks of more than 3,000 feet as well as wade through bogs and marshes. And in a couple of places we had to use our hands."
The officer set off at 6am in the dark but ended up completely off course.
It was only when the sun came up and he noticed other groups a mile away, that he realised he had gone the wrong way.
John, who said he was in 'agony' the next day, is already planning his next trip. "I'd like to do another three peak challenge he said. Possibly Mount Snowdon, Ben Nevis and Scafell Pike in the Lake District."
All money raised is going towards the Krishna Avanti Primary School in Harrow.