In the vast sea, there is the mountain of Dushuo. There is a large peach tree on it, which has a bend of three thousand miles. The northeast branch between its branches is called the ghost gate, where all ghosts come and go. There are two gods on it, one is called Shen Tu and the other is Yu Lei, who oversee and guide all ghosts.
——Wang Chong of Han Dynasty quoted from "Lunheng·Dinggui" from "The Classic of Mountains and Seas"