Foggy valley: The unique geological conditions of numerous valleys and thick forests, together with a high precipitation and high degree of humidity, all contribute to the thick fog that lasts almost all day long in the valley. According to the local Yi people, one should speak in a low voice here not to disturb the mountain god, otherwise, he will produce a thick fog that will sweep away all signs of life. Scientists believe that one of the most plausible reasons for the disappearance of human beings and livestock in the area is the fog since it is difficult for travelers to find their way around in the thick fog, especially given the perilous and complicated geological conditions. Others also argue that the deaths and disappearances may be attributable to some unknown poisonous component in the fog in some parts of the valley. However, this supposition is yet to be confirmed.

Special fauna and flora: The valley is also teeming with a great number of wild animals and plants, many of which are very rare. Twenty-nine kinds of animals, including the panda, antelope, macaque and lesser panda, are under State protection in this region. With the highest point in the valley at 4,299 meters and the lowest at only 1,233 meters, the great drop in latitude has caused varied vertical vegetation. Nineteen kinds of plants, like the Nyssaceae, are also under State protection, among which many are exclusive to China alone. The valley is home to more than 10,000 mu  (about 666.66 hectares) of 40 different kinds of azalea flowers, ranking No 1 in scale across the world. The plants  in Heizhu Valley have a long history and ancient origin. Due to its special geological conditions, the region has rarely been disturbed by humans throughout history, and it was also unaltered by the Quaternary Period glacier. As a result, the valley has provided a very good environment for the reproduction of plants and a great number of ancient and rare plants have thrived there.