Atlantis

Atlantis was a mythical Earth island, thought to have existed at some point in the past.

Upon discovering the Native American colony on the planet Amerind, James T. Kirk compared it to discovering Atlantis or Shangri-La. 

In 2364, William T. Riker in comparing the myths of Atlantis, Neinman, and the planet Aldea, described them as "self-contained, peaceful, with incredible technical sophistication which provided for every citizen's daily needs, allowing them to devote themselves to culture and art, which was beautiful beyond compare and valued beyond price."

By the latter half of the 24th century, Earth scientists had devised a project dubbed "the Atlantis project" as a way of creating a new continent in the Atlantic Ocean, much like Atlantis once did.