For the first time ever, a person has scaled Niagara Falls while it's in a frozen state. Ice climber Will Gadd braved the treacherous, unstable climbing conditions to complete the stunt. He explained the challenges of his frozen feat:
"The ice is formed in layers. That means there's a layer of ice, then snow (with a lot of air), then another layer of ice. It's unstable, for sure."
Gadd used ice axes, crampons and a specially-designed ice hook to climb the falls. Read a more detailed account of Gadd's climb here.
Images: Christian Pondella