Mu was an immense continent covering nearly one-half of the Pacific Ocean. When she sank during volcanic destruction, fifty million square miles of water claimed her place. This vast continent and culture was the centre of civilization some 25,000 years ago. This work presents the story of the author's search for the lost continent.

This classic book on the theory of a lost continent in the Pacific, first published in 1931, imparts the fascinating travel stories and theories of James Churchward, in a large format edition, with a all-new introduction by David Hatcher Childress.

Chapters include:
Alpha The Beginning
The Lost Continent
The Land of Mans Advent on Earth
Records of this Lost Continent
Mu, the Empire of the Sun
Age of Mus Civilization
North Americas Place Among the Ancient Civilizations
Nivens Mexican Buried Cities
The Geological History of Mu

James Churchward (1851-1936), was a British occult writer, inventor, engineer, and fisherman. He was the elder brother of the Masonic author Albert Churchward (1852–1925). Churchward is most notable for proposing the existence of a lost continent, called "Mu," in the Pacific Ocean. His writings on Mu are considered to be pseudoscience.

Churchward claimed to have gained his knowledge of this lost land after befriending an Indian priest, who taught him to read an ancient dead language (spoken by only three people in all of India). The priest disclosed the existence of several ancient tablets, written by the Naacals, and Churchward gained access to these records after overcoming the priest's initial reluctance. His knowledge remained incomplete, as the available tablets were mere fragments of a larger text, but Churchward claimed to have found verification and further information in the records of other ancient peoples.

According to Churchward, Mu "extended from somewhere north of Hawaii to the south as far as the Fijis and Easter Island." He claimed Mu was the site of the Garden of Eden and the home of 64,000,000 inhabitants- known as the Naacals. Its civilization, which flourished 50,000 years before Churchward's day, was technologically more advanced than his own, and the ancient civilizations of India, Babylon, Persia, Egypt and the Mayas were merely the decayed remnants of its colonies.

In 1926, at the age of 75, he published The Lost Continent of Mu: Motherland of Man. His writings attempt to describe the civilization of Mu, its history, inhabitants, and influence on subsequent history and civilization. Churchward claimed that the ancient Egyptian sun-god Ra originated with the Mu; he claimed that "Rah" was the word which the Naacals used for "sun" as well as for their god and rulers.