Overview of the Planes in Scarterra

I'm still working on the finer details but I have the basics down.
Material Plane
The Material Plane or the Mortal Plane is where most RPG adventures and stories happen. It is metaphysically the earth and sea.
Scarterra is shaped liked a cylinder. Mortals and beasts live on the flat side of the cylinder and the poles of the cylinder are portals to the Void.
The distance between the north and south pole is roughly 4000 miles. Circumnavigating the world east to west is 12,000 miles as the dragon flies. Thus the habitable portion of the Material plane is 48,000,000 square miles roughly equal to the surface area of real world Mars.

Aetherial Plane
The Aetherial Plane is metaphysically the sky. This is where the Nine have their own private subrealms and it's where the Honored Dead live their afterlives.
The Nine's spirit minions spend most of their time here. They are born here.

The Void
Metaphysically and somewhat literally the Void is on the edge of the world. If one goes north of the north pole or south of the south pole, one would walk into the Void. The Void is a malevolent nothingness that seeks to snuff out all life, all heat, all souls.
The Void was created after Turoch was slain and represents Turoch's hunger and anger. Void Demons are spawned here.

The Elemental Plane
The Elemental Plane exists in the core of Scarterra's cylinder and is in a way the engine or battery that makes life possible. Elementals spawn here and many spells draw energy from this plane, but not mortals may travel there and survive.

The Astral Plane
I'm still working out the details of the Astral Plane. The Astral Plane contrasts with the Void as a benevolent nothing representing thought and possibilities. The Astral Plane is everywhere and nowhere touching all the other planes.

The Fae Realm
The Fair Folk live here primarily. The Fae Realm exists parallel to the Material Plane and the two planes are connected through various Faerie Gateways.
Beyond this I haven't come up with many concrete details or rules. Part of this is a WIP and part of this is deliberate. I want the Fae Realm and the Fair Folk to be mysterious and not very well known, so stories with the Fair Folk can be fast and loose.