A free runner has decided the daredevil sport wasn't providing enough adrenaline alone - and has stripped off to do it while naked.
The nail-biting activity hardly needs more excitement, but free running world-champion Tim Shieff and photographer David Paul obviously thought it did.
The decided to carry out the amazing photo shoot around London, called Man & Mortar.
It sees Shieff jumping across buildings, hanging off balconies and running down underground walkways - all without an clothes on.
According to the Independent, the idea was borne during a trip to Greece.
Shieff said: "We were in Greece on a free running and thought that it didn't quite fit the surroundings, and it just came to us, why not do it naked.
"It really fitted with the black and white style and we thought why don't we continue this theme."
He added: "In London, we got some better photos than we did in the first shoot; the architecture just lent itself so well to what we were doing."
The Mirror reports that in an interview with Wake Up London, Sheiff said they hardly got noticed. He even got nude on an empty Tube train.
"There was quite a lot of the time when we would do it on rooftops and we would look down and there would be hundreds of people walking underneath you around Bond Street and not one person would look up."
Shieff added that he hoped the shoot would bring more attention to the sport.
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