The original inhabitants of Guam and the Northern Mariana Islands were the CHamoru people, historically known as Chamorros. The ancient CHamoru society had four classes: (chiefs), (upper class), (middle class), and (lower class). The were located in the coastal villages, which meant they had the best access to fishing grounds, whereas the were located in the island's interior. and rarely communicated with each other, and often used as intermediaries. There were also "" or "," shamans with magical powers and "'" or "," healers who used different kinds of plants and natural materials to make medicine. Belief in spirits of ancient CHamorus called "" still persists as a remnant of pre-European culture. It is believed that "" or "" are the only ones who can safely harvest plants and other natural materials from their homes or "" without incurring the wrath of the "." Their society was organized along matrilineal clans.