Gaiyu Town has the custom of tree burial. Some have four or five on a tree, and some have only one or two, like a beehive built by a beekeeper. Most tree burials are minors under the age of 13. Tree coffins are generally made of fir boards, and some are made of cypress. The boards are inlaid with concave and convex, and fixed with bamboo nails around. Locals generally do not use round nails. It is said that round nails will nail the soul and prevent it from transcending to heaven. Generally, families with high infant mortality rates hang wooden boxes high up. After the death of baby girls, they are usually hung at the bottom. Some people cremate the bodies and put them in mud pots and then hang them on fir trees. The selection of tree burial sites is very strict. One is at a T-junction or a crossroads, which symbolizes that there are always people accompanying the dead; the second is where two or more rivers meet, and the rivers are like mother's milk, flowing into the hearts of the dead; the third is that the selected tree must be grown on a grass dam at a crossroads or the center of the confluence of two rivers. The tree must be thick and tall, with lush branches and leaves, symbolizing a prosperous population and successors.