Not all of the Rim of the Grand Canyon is flat and easy to approach. You could get the impression, if you only visited the developed portions of the Rim, that the Canyon was something you can walk over to easily and look at. In some places, it is rugged and extremely dangerous to approach the edge. It seems that people who go to these places know this and respect the Canyon. Most of the falls into the Canyon seem to come from people in the developed areas.