Pacifica is a wholly water planet, named after Earths largest ocean. Pacifica is one of the few planets to have undergone no terraforming, as the water and air are already perfectly suited to human life. The surface of Pacificntirely water, however, with land being far too deep to ever be raised. Thus, nearly the entire population lives in underwater cities. Due to the defensive advantages of being deep underwater, Antlanterra is incredibly difficult to siege from orbit.
The majority of Pacifica's habitable area is in underwater cities constructed long before The Singularity to support a population far exceeding what lives there now. Much like Lunath's Clockwork, these massive cities feature a high level of mechanization and modularity, equipping the whoever controls the cities to consolidate power and crush or conquer other bodies with ease. The myst does not have a significant presence on Pacifica, though some aquatic galatea sometimes appear from the unused parts of the ocean, and stranger things from the deepest trenches in its floor.
Pacifica is the only planet in The Systems controlled entirely by the Avalon Empire. The Atlantean Suzerainty has held Pacifica for well over a century without opposition. Outward expansion from there stable, fortress of a homeworld is their only concern