COOL STUNTS | Alex Honnold: El Sendero Luminoso  
Imagine climbing to the top of a 2,500-foot cliff without climbing ropes or safety gear of any kind. It's called free-soloing, and Alex Honnold is one of the best at it. In this video, he makes his way to the top of Mexico's El Portero Chico -- possibly the most difficult rope-less climb in history.