"The Atlantean A is a shape developed by John Emerson. It is a miniature map of the city of Atlantis (i.e., the outside of the swirl is the cave, the inside shape is the silhouette of the city, and the dot is the location of the crystal).  It's a treasure map." - Kirk Wise, Atlantis: The Lost Empire - The Illustrated Script (Abridged), p. 82