Pfortenbuch
The Coffin Texts included sections with detailed descriptions of the underworld and instructions on how to overcome its hazards. In the New Kingdom, this material gave rise to several "books of the netherworld", including the Book of Gates, the Book of Caverns, and the Amduat. Unlike the loose collections of spells, these netherworld books are structured depictions of Ra's passage through the Duat, and by analogy, the journey of the deceased person's soul through the realm of the dead. They were originally restricted to pharaonic tombs, but in the Third Intermediate Period they came to be used more widely.