Sanctum sanctorum is a Latin term that refers to the most sacred and protected place within a temple or spiritual institution. This term is often used metaphorically to refer to a person's innermost self or private space. There are several synonyms for sanctum sanctorum, including holy of holies, inner sanctum, sacred chamber, secret place, private space, sanctuary, and holy place. Each of these phrases conveys the same sense of privacy and protection of a person's innermost thoughts and emotions. Whether in a literal or metaphorical sense, the sanctum sanctorum is a place of great significance and reverence.