Among the first major post-Flood achievements, the Human Arcs are the oldest and most historical cities on--or above--the planet. Most of the human race resides on these Arcs, and one of these monoliths, Avaris, serves as the capital of the world.

The droids, in replication of their human counterparts, decided to build their own Arcs as well. In conjunction with the humans and mutants, these Arcs were raised to a different part of the world. Though in shoddier condition, these monoliths will remain in the sky for ages to come.

The New Lands are actually where all post-Flood society re-civilized before creating the Arcs. The mutants as a whole decided to continue to reside in these lands instead of in the sky. Here, they can commune with the Eonmind more directly and are free from the bounds technology has on them.