An immured anchorite, considered by many to be a myth, is a Tibetan monk who has taken a vow to spend his life permanently sealed inside a small walled cell. The walled cell, only large enough for the monk to sit in meditation, has only a single stone that is moved to offer bread and water once a day. The cell has no windows and the monk spends his life in complete darkness. The concept of an immured anchorite was also used in the novel The Wheel of Darkness by Douglas Preston and Lincoln Child.