The New Atlantis Project, generally referred to as just the Atlantis Project, was a project initiated in 2367 as a way of creating a new subcontinent on the Mid-Atlantic Ridge in the Atlantic Ocean on Earth. Information on this project was available through the New Atlantis Development Project Presentation Database.
It was supervised by 200 people, including Louis, a childhood friend of Jean-Luc Picard, but lacked a satisfactory director who would lead the project. One of the challenges was to accelerate the build-up on the underside of the mantle without increasing the stress on the tectonic plates. During his explorations on the USS Enterprise-D, Picard had kept up with the project through journals.
For the emergency background chatter for the Starfleet Command scenes in Star Trek IV: The Voyage Home, there were lines written which mentioned Commander Christine Chapel sending a message to "Governor Okuda" of "New Atlantis". (Star Trek Encyclopedia (4th ed., vol. 1, p. 49))