Atlantis Arcology

The Atlantis Arcology, nominally the Atlantis-NS Arcology District is a Terran arcology located on Earth. It is by far the most populated settlement in the Galaxy housing over half a billion people. The Atlantis Arcology was the first and one of only three undersea arcologies built on Earth. It is renowned for its massive industrial sector and for housing the headquarters of several large Terran corporations, most notable of which is GA. However the arcology is also known for its lawlessness especially in the lower districts, as well as the disparity in living standards and wealth between the upper corporate and lower civil districts.
In 2567, the arcology was struck by a major disaster when leaks caused by poor maintenance flooded the bottom ten districts. The industrial areas hit liberated many toxic gases which poured up until the 200th level. The usual lawlessness of the arcology drastically worsened. The Federal army was unable to deploy quickly enough to restore order, and so Siems private security were sent to restore order in the lower levels, in fire and blood. By 2570, the arcology had been fully repaired, however its image took a much longer time to recover.