The Atlantis Project was a project in early to mid-24th century which attempted to construct a new continent in the Atlantic Ocean on Earth.
The first man-made island of the Atlantis Project was Platonis, which was later followed by Poseidonis. (NF novel: Stone and Anvil)
Jean-Luc Picard was offered a lead position on the project by Louis Blanchard following his separation from the Borg in 2367. (TNG episode: "Family")
In 2375, during the Dominion War, the Dominion sent Jem'Hadar and Breen soldiers to investigate the Atlantis Project. (TNG short story: "Solace in Bloom")