The w:Desert View Watchtower in Grand Canyon National Park, Arizona. The particularity of hiking in a canyon is that it starts to go down ... and the return is going up, unlike mountain walks. This feature makes the hike in the Grand Canyon can be dangerous because it is very easy to get off and much more difficult to trace. However, some hikers will stop down as they begin to be tired or hungry. So many signs "Danger of death" are displayed at the beginning of the descent to inform tourists of the dangers.