""Mysteries of Tannhauser"" is a spiritual and philosophical book written by Max Heindel. The book explores the hidden mysteries of the Tannhauser legend, a medieval tale about a knight who visits Venusberg, a mythical mountain where the goddess Venus resides. Heindel uses the legend as a metaphor to explain complex spiritual concepts such as the nature of the soul, the meaning of life, and the role of love and sexuality in spiritual evolution. He...