Atlantis

Map of the Atlantean Empire, from Ignatius Donelly's Atlantis: the Antediluvian World, 1882.

Plato's account

Reed Carson articles and recommended reading list at Blavatsky.net. [1]
"Atlantean Realities." Philaletheians web page. [2]
Bartzokas, Chris A. ed., Rise and Demise of Atlantis: Occult Features of the Fourth Race of Humanity and Its Fall into Matter. Available on Philaletheians web page. [3] ISBN 978-0-9550400-5-4. Beautifully illustrated work references The Secret Doctrine and other sources.