[2][3][4][5] The mythical idea of the "Land of Mu" first appeared in the works of the British-American antiquarian Augustus Le Plongeon (1825–1908), after his investigations of the Maya ruins in Yucatán.

[8] Le Plongeon identified this lost land with Atlantis and, following Ignatius Donnelly in Atlantis: The Antediluvian World (1882), identified it as a continent that had once existed in the Atlantic Ocean: In our journey westward across the Atlantic we shall pass in sight of that spot where once existed the pride and life of the ocean, the Land of Mu, which, at the epoch that we have been considering, had not yet been visited by the wrath of Human, that lord of volcanic fires to whose fury it afterward fell a victim.

The description of that land given to Solon by Sonchis, priest at Sais; its destruction by earthquakes, and submergence, recorded by Plato in his Timaeus, have been told and retold so many times that it is useless to encumber these pages with a repetition of it.[6]: ch.

[9]: 7 The tablets begin with the creation of Earth, Mu, and the superior human civilization Naacal by the seven commands of the seven superlative intellects of the seven-headed serpent Narayana.

[10] Churchward gave a vivid description of Mu as the home of an advanced civilization, the Naacal, which flourished between 50,000 and 12,000 years ago, was dominated by a “Melanated/Black race",[9]: 48  and was "superior in many respects to our own".

[11] He claimed that according to the creation myth he read in the Indian tablets, Mu had been lifted above sea level by the expansion of underground volcanic gases.

Eventually Mu "was completely obliterated in almost a single night":[9]: 44  after a series of earthquakes and volcanic eruptions, "the broken land fell into that great abyss of fire" and was covered by "fifty millions of square miles of water.

"[9]: 50  Churchward claimed the reasoning for the continent's destruction in one night was because the main mineral on the island was granite and was honeycombed to create huge shallow chambers and cavities filled with highly explosive gases.

[12] Churchward claimed that Mu was the common origin of the great civilizations of Egypt, Greece, Central America, India, Burma and others, including Easter Island, and was in particular the source of ancient megalithic architecture.

"[9]: 138 As additional evidence for his claims, Churchward looked to the Holy Bible and found through his own translations that Moses was trained by the Naacal brotherhood in Egypt.

The platforms on which the statues rest (ahu) are described by Churchward as being "platform-like accumulations of cut and dressed stone", which were supposedly left in their current positions "awaiting shipment to some other part of the continent for the building of temples and palaces".

[9]: 54 In the 1882 book Oahspe: A New Bible, John Newbrough included a map of the Earth in antediluvian times (i.e. prior to the great flood of biblical record) where an unknown continent is located in the Northern Pacific.

[15] James Bramwell and William Scott-Elliot claimed that the cataclysmic events on Mu began 800 thousand years ago[16]: 194  and went on until the last catastrophe, which occurred in precisely 9564 BC.

Over the scale of history (tens of thousands of years), the sima under the continental crust can be considered solid, and the continents are basically anchored on it.

[21] Furthermore, while Churchward was correct in his claim that the island has no sandstone or sedimentary rocks, the point is irrelevant because the pukao are all made of native volcanic scoria.