The Hall of Records is a purported ancient library that is claimed to exist underground near the Great Sphinx of Giza in Egypt. The concept originated with claims made by Edgar Cayce, an American who claimed to be clairvoyant and was a forerunner of the New Age movement. He said in the 1930s that refugees from Atlantis built the Hall of Records at Giza to preserve their knowledge. Cayce's assertions had many precursors, particularly the pseudohistorical theories about Atlantis that Ignatius Donnelly promulgated in the late 19th century, as well as claims about hidden passages at Giza that date back to medieval times.
In the 1990s, Cayce's claims about the Hall of Records became conflated with two other fringe hypotheses about the origin and age of the monuments at Giza: the sphinx water erosion hypothesis and the Orion correlation theory. Adherents of these ideas came to adopt Cayce's date of around 10,500 BC for the origin of the sphinx. Many hoped the Hall of Records would soon be discovered, thus lending credence to the occult and New Age beliefs with which these hypotheses were frequently connected. Although the increased public attention to the site prompted the full exploration of a tomb known as the "water shaft" in 1999, nothing fitting Cayce's description has ever been found.