As stated before Bouldering is only about 15-20 feet tall. Since it is short a harness and rope is not needed. Instead a mat and proper falling technique is needed to be safe. To learn more about properly (put link)Falling Click Here. Bouldering is usually what beginners try first as it is simpler and takes less prep time than top rope. This is also more popular because people with a fear heights aren't as scared because it is very short.