A team of cold-weather enthusiasts in Finland have spent the last week trying to carve a huge, perfect circle into a frozen lake to build the world's largest "ice carousel".
The more than 300-metre wide spinning ice disk in Lappajarvi, western Finland, is powered by a boat motor and must perform a full rotation in order to claim the world record.
"If it's not perfectly round, it does not go around, so it has to be measured precisely," ice enthusiast Thor-Fredric Karlsson told AFP on the frozen lake.
The project is the brainchild of inventor Janne Kapylehto, who hopes to complete the attempt on Monday.
Kapylehto claims to have come up with the ice carousel idea in 2017 when he posted a video online of his first creation.
Since then others around the world have followed suit, creating increasingly ambitious spinning ice circles, leading to Guinness World Records creating a "world's largest ice carousel" category.
If successful, Kapylehto's effort will win him a fifth world title, snatching the record from a team in Minnesota in the United States whose 225 metre (738 foot) carousel is the current title holder.
"It's pretty crazy," the Finn admitted to AFP, adding that his team was cutting the 900-metre perimeter circle using chainsaws and two specially built machines christened "the hurricane" and "the red devil".
The renewable energy specialist says he has now built over 60 carousels, while his previous exploits include sailing a solar-powered floating sauna 90 kilometres (55 miles) from Helsinki to Tallinn in 2018.
The Lappajarvi carousel contains a smaller rotating disc within it, and was commissioned by the local authorities who wanted to raise awareness of how climate change is shortening the Nordic country's winters, meaning lakes no longer freeze over as regularly.