Religion played a major role in ancient societies' approaches to health and medicine. In many cultures, illness was believed to be caused by displeased gods or spirits, so treatment involved rituals and sacrifices to satisfy them. Some ancient Greeks consulted temples of gods like Apollo and Asclepius for cures. Places called asclepeia were built as healing temples where the god Asclepius was believed to visit and cure people in their sleep through dreams. The asclepeia were run by priests and some accounts of cures were recorded, with snakes as symbols of healing.