Midgard City is a city-state built by Noriko Null in Antarctica, constructed above the previous Midgard Station.

It is not part of any country and its land is privately owned by Null Technologies, populated by immigrants coming from all over the world.
Its mayor is Oluwa Kalu, a former Nigerian winner of the Nobel Peace Price.

It houses the projector of a planetary shield that was used to protect Earth from an invasion of the Ares fleet.