There are people out there who choose to climb mountains taller than the Empire State Building completely alone, without ropes or any safety equipment. The most famous of these climbers is Alex Honnold, who recently climbed a skyscraper even taller than the Empire State Building!
These adrenaline junkies flew under the radar for a long time, but in the past decade, the art of free soloing has made it onto the world stage. This is in no small part thanks to the high-profile escapades of climbers like Honnold.
Click through this gallery to learn about this extreme sport and those who have mastered it.