A man who ran the road circling Iceland in 17 days has said it was "surreal" to cross the finish line.
Sebastian Key, 25, from Sherborne, Dorset, ran the 786-mile (1,265km) road to raise money for Children With Cancer UK, documenting his progress on Instagram.
He was inspired by his younger sister Libby Key, now 20, who was diagnosed with a brain tumour at 11 weeks old.
He is now hoping to claim a world record for the challenge, with the only other known run around Iceland being completed in 27 days.
Mr Key said he grappled with "hectic" weather and several injuries but it was "absolutely" worth it for the money and awareness he raised.
He said he had "always" wanted to raise money for Children with Cancer UK, which he also works for.
Mr Key ran the equivalent of two marathons every day, split into four sections with food breaks in between.
He got injured on day three, and has also grappled with Achilles tendinitis and tenosynovitis in his feet, explaining he was "in a bit of a state".
He said it was only because of his physiotherapist, Tommy Jermyn, that he was able to continue.
"For 12 days I ran with rubber bands strapped to my shins to help my feet lift up," he said.
The weather was also a challenge. Mr Key said he faced sub-zero temperatures, heavy rain, and wind so strong he "couldn't even run in a straight line".
Mr Key is now waiting for confirmation of a world record, explaining: "The only known person who's run it before took 27 days and that was an amazing guy.
"We did it in 16 days and 10 hours, so we're claiming the record unofficially. No one has stuck their hand up and said they've done it faster, so now we're looking to try and get it certified."
Mr Key said the support he received along the way - particularly from the team of five "unbelievable friends" that travelled with him - kept him going.
"In some of the darkest days, the main thing that kept me smiling was that they were there with me," he said.
He added he was also motivated by the cause he was raising money for.
"People would say 'maybe take a rest day' [but] I thought these families don't get a rest day."
"You get up and you keep going."
His sister was there when he crossed the finish line in Reykjavík, and said she was "so proud" of him.
"I spent most of the day crying because I just am incredibly in awe of what he's done," she said.
And Mr Key thinks it was worth the struggle: "It was the most difficult and exhausting thing I've ever done, and yet I would do it again if I knew it would have the same impact.
