Mu
Mu is a lost continent introduced by Augustus Le Plongeon (1825–1908), who identified the “Land of Mu” with Atlantis. The name was subsequently identified with the hypothetical land of Lemuria by James Churchward (1851–1936), who asserted that it was located in the Pacific Ocean before its destruction. The place of Mu in both pseudoscience and fantasy fiction is discussed in detail in Lost Continents (1954, 1970) by L. Sprague de Camp.
Geologists state that the existence of Mu and the lost continent of Atlantis has no factual basis, and is physically impossible, as a continent can neither sink nor be destroyed in the short period of time asserted in the legends, folklore and literature about these places.
Lost Continents: The Atlantis Theme in History, Science, and Literature is a study by L. Sprague de Camp that provides a detailed examination of theories and speculations on Atlantis and other lost lands, including the scientific arguments against their existence. It is one of his most popular works. It was written in 1948 and first published serially in the magazine Other Worlds Science Fiction in 1952–1953; portions also appeared as articles in Astounding Science Fiction, Galaxy Science Fiction, Natural History Magazine, and the Toronto Star. It was first published in book form by Gnome Press in 1954; an updated edition was published by Dover Publications in 1970. De Camp revised the work both for its first book publication and for the updated edition.