It is a place where Yin and Yang clash. The soul-chilling Yin winds that blow yearlong are enough to scatter a Nascent Soul. The cave is also host to several kinds of vicious ghosts. Even if a living person is able to endure the Yin winds after entering the cave, the ghosts will devour them. Several kilometers deep, there are countless chains of intertwining passages and caves. The Yin winds obstruct cultivators from releasing their spiritual sense.
In the Yin Yang Cave was trapped the Silver-winged Nightfiend in the Spirit Prison Formation by ancient cultivators. The formation was set to teleport the creature to the Kunwu Mountain, if the mountain's seal would be broken.