whats the original purpose of doing that?
to be left alone, secluded, to be safe from attacks, or what?
It is a Daoist mountain. The Daoists believe a god lives in the mountain and it was a favorite place with Daoist hermits. The paths were the only ways to get around the mountain. Due to its steep sides, the mountain didn't lend itself well to paths or stairs, so this was the only way to move around on it. Now though they have carved paths into the mountain and even added a cable car. A lot of people still want to go the dangerous route though.