Alex Honnold.

The person sitting on that ledge is Alex Honnold. He’s been proclaimed the best free soloist (i.e., climbs without ropes) in the world. The startling image above (posted to Reddit and tracked down to photographer Tim Kemple) shows Mr. Honnold midway up Half Dome, an incredibly challenging granite dome in Yosemite National Park 4,737 ft (1,444 m) above the valley floor.

For us mere mortals this appears as absolute insanity. How can someone climb such incredibly difficult faces without a rope? If you’re still intrigued, I highly recommend the 15-minute special 60 minutes did with Alex