A Welsh explorer says he is the first person to complete a 4,000-mile (6,437km) trek along the length of the Yangtze river in China.
Ash Dykes, 28, from Old Colwyn in North Wales, said he finished the year-long journey on Monday.
On the expedition, he said he endured altitudes of more than 5,000m (16,400ft), blizzards, and temperatures as low as -20C (-4F).
Mr Dykes said: “It’s an unreal feeling to cross the finish line.
“It took two years to plan and one year to execute, so it’ll take a while to sink in.
“But it’s such a special moment – history is created.”
A team that was due to walk with Mr Dykes dropped out before the trip began, after they said that the source of the Yangtze was too difficult to reach, and there was a risk of being attacked by wolves and bears, he said.
Mr Dykes claimed that in the early stages of the trip, he was followed for two days by a pack of wolves, which had recently killed someone.
He then met up with another group of walkers later on in the trip, which accompanied him on the expedition.
Mr Dykes added: “This has been more than a personal achievement – it is unlocking human potential and showcasing that, in a world where every corner of the planet is occupied by people, there are still things that haven’t been done.
“It has also been far from just a challenging journey, as it’s been a cultural one too.”
The Welshman used his trek to highlight conservation projects by organisations such as the the World Wildlife Fund and the Green Development Fund.
He also recorded the amount of plastic and pollution he saw along the way.
He said: “The good news is that I’ve seen a huge increase in knowledge and understanding within the communities, towns and cities along the way.
“People are aware of the damage being caused to their water sources and are now actively changing their ways for the better – it’s inspiring to see.”
His completion was delayed by two days after Typhoon Lekima scuppered his original finishing attempt.
It is not the first trip undertaken by Mr Dykes – in 2014 he became the first person in recorded history to walk unsupported, from west to east across Mongolia, which took him 78 days.
He also traversed the length of inland Madagascar, trekking 1,600 miles (2,575km) over eight mountains in 155 days in 2016 – becoming the first person to do so.