"These are humans, usually described as being benevolent by comparison to other groups, who are said to inhabit vast and complex cavern-cities beneath southern Brazil and surrounding regions. The term 'Atlantean' or 'Atlan' in reference to these races, has been placed upon them because of the fact that these cavern networks along the east coast of Brazil were reportedly once a part of the antediluvian 'Atlantean' empire. The present inhabitants have no direct GENETIC relation to the ancient 'Atlantean' society which is said to have controlled these cavern systems several millennia ago, but are referred to as 'Atlanteans' simply because they are descendants of those who re-discovered and inhabited the ancient Atlan installations. As in North America and other continents, both common and gnome-like humans have been encountered here, some of which possessed advanced aerial or 'disk' technology. The Telosians claim to have some connections with South America, especially the Matto Grosso region where a sister city named POSID exists in a large cavern system underground." source



Disclaimer: please view this material as exploratory, even metaphoric, if you like.