Catherine Destivelle Credit: Corbis Images In its most well-protected form, rock climbing is a relatively safe sport. With harnesses, ropes, bolts, belay gear and good training, risks rival other sports and the most likely injuries are fractures, strains and sprains.
For some climbers, though, protection takes away the essence of the sport. Without ropes and other obstacles, proponents of free soloing say their sport offers a kind of focus, simplicity and speed that other forms of climbing can't touch.
Free soloing also offers the possibility of death at any moment. If a rock ledge breaks, or sweaty fingers slip at hundreds or thousands of feet up, chances are not good for survival.
All of that may explain why it is so mesmerizing to watch climbers as they free solo difficult routes. Even if you think it's outrageous to take those kinds of risks, I dare you to tear your eyes away.
The video above, for example, shows Swiss mountaineer Ueli Steck in 2008, as he cruised up the Eiger, a 13,025-foot mountain in Switzerland, in record time. Stech finished the technical route in two hours, 47 minutes and 33 seconds. It was just a year after he had set the previous record of three hours and 45 minutes.
The video, created for the 2010 Reel Rock Tour by Sender Films, shows a man in constant and quick motion - even when he reaches an ice field near the top of the mountain. The energy required to accomplish such a thing is hard to fathom.
And as long as we're on the topic of free soloing, here's another one worth watching. Shot in 1987, it shows French climber Catherine Destivelle on a sandstone cliff in Mali.
She is pure art in motion and beautiful to watch. The culture of the place infuses her spirit of adventure and adds entertainment value to the video. But when she reaches the roof, your jaw will drop. Luckily, she manages to hang on.