Kireon - The Prime Material Plane
When most mortals refer to "Kireon", they are actually referring to the Prime Material Plane. This is the Inner most concentration of Reality. Divine Beings must risk great pains to reach this plane, and while there, their powers are... different. They can't alter it as easily as they can their own domains.
The prime material sits at the crux of several other planes that reflect it.For more information on the physical contents of this plane of existence, refer to The Encyclopedia of Corporeal Environs.