Do you have a name for the activity, going down on a cliff with a roap on your body? This activity seems to be a sport, an extreme sport.

I think you mean rappelling.

https://www.google.com/search?q=rappelling&spell=1&sa=X&ved=0ahUKEwiZ3rOE_ungAhVEQq0KHVKPDyEQBQgpKAA&biw=1250&bih=618

Yes, the activity you're referring to is called "abseiling" or "rappelling." Abseiling is a method of descending a steep cliff or vertical surface by using ropes and specialized equipment. It is indeed considered an extreme sport and is popular among thrill-seekers and outdoor enthusiasts. Would you like me to explain how one can participate in abseiling or provide more information about the sport?