Most of the "evil-killing gangs" are set up in roadside, lakeside, crossroads and other places. The stone piles are small in size and conical in shape. There are no steps. The right pile contains the evil curse and the spear of the town. Most of the stones, slates or pebbles are engraved with words and images, mostly Tibetan Buddhist scriptures, Buddha statues, animal protection gods, six-character mantras and various auspicious patterns.
On auspicious days, people add stones to the Nima pile while simmering mulberry, and touch it with their foreheads devoutly. They keep praying for a long time, and the Nima piles will rise from the