The great quicksand is a famous danger point on the Bing_Cha_Cha line.Locals call it the death zone.Bing_Cha_Cha line,It is a road from Yunnan bingzhongluo via Tibet Chawalong to Chayu, due to the complex geological structure along the treacherous terrain, this line is still only a few explorers and senior outdoor players yearn for the paradise. The great quicksand, seen from a distance as a huge smooth concrete slope, is actually a landslide of mountain rubble, mainly hard gray stone, which is uniform in size, about the size of an egg, and sometimes smaller, as if it had been carved. Through the ages, whether it is the Tea Horse Ancient Road or the road developed on the basis of the Tea Horse Ancient Road, we must pass through the big quicksand. Big quicksand terrible lies in, hard stones, at any time may fly down from the top of the distant mountains, rolling speed is very fast, big stones in the rapid way was knocked into rubble. Some fell on steep stone slopes, and some crashed heavily into the Nujiang River.