The name of the hypothetical vanished continent Mu originated from the first attempted translation of the Madrid Codex, one of only four remaining Maya codices.
Sanskrit
Something similar seems to have happened upon the discovery of the Sanskrit literature by Europeans. Louis Jacolliot claimed to have learned from this literature about a sunken continent called Rutas. This in turn seems to have influenced Madame Blavatsky and her speculations about Lemuria. Speculations about Kumari Kandam also seem to be linked to this field. The name Lemuria originated from the scientific hypothesis about a land bridge between India and South Africa. With the discovery of the continental drift, however, this hypothesis is now considered obsolete.
Medieval European
Other mythical continents include Terra incognita, such as Terra Australis Incognita, which were probably based on garbled accounts from early explorers, but subsequently shown to have a basis in reality, and to be valid after scientific investigation and concept refinement.