Introduction to Frightening Gorge: Frightening Gorge is 700 meters long. It is the most spectacular underground canyon discovered in China so far. The two sides of the canyon are like being cut with knives and axes. It is nearly 100 meters from the bottom of the canyon to the top of the cave. It is the narrowest part in the canyon. It is only three or four meters wide, and every visitor feels thrilling when walking through it.