A 'shimenawa' rope is wrapped around a sacred guardian tree at one of Japan's Hachiman Shrines.
Sacred trees, called shinboku, are a deeply ingrained part of a Japanese culture that has historically viewed itself as being united with nature, rather than separate from nature; thus, recognizing the sacredness of trees, stones, mountains, forests, and the elements has been a relatively constant theme in Japanese culture for thousands of years.[6][7] In the present day Japan, shinboku are trees inhabited by kami (spirits or deities) and can readily be found in many of the 100,000 Shinto shrines existing in throughout the country. Although any tree can technically become a shinboku through a Shinto ritual process of inviting a kami to inhabit it, most shinboku are particularly large or aesthetically interesting examples of endemic species such as camphor, ginkgo, or Japanese cedar. The oldest shinboku are estimated to be several thousands years in age. Because shinboku are viewed as being literal sanctuaries, inhabited by kami, they are protected as a physical and spiritual embodiment of the divine nature. In most cases, Shinboku can be easily identified by the straw or hemp rope called a shimenawa which is typically wrapped around the tree; the rope acts as both a sign of the tree's sacredness, and also as a protective barrier between the spirit world and the human world.

In addition to individual shinboku, shrines and Buddhist temples are often surrounded by sacred forests called chinju no mori, which are considered sacred forests where kami, including spirits of ancestors, dwell.