Nerath

The world of Nerath, the default world of the Dungeon Master's Guide 4th edition, was a world on an alternate Material Plane.

People
The deva Demascus was originally from this world.

Deities
Deities from this world were summoned in the Dawn War, to help the gods of the Realmspace to defend the newly born worlds of this Material Plane against the primordial threat. It's not known if those gods remained on the Realmspace after the war.

History
The abyssal plague was originated from this world.

Trivia
This world is also called the "Points of Light" world.

According to Chris Perkins, the Nentir Vale (a region of this world) was originally conceived to be part of the Realms, before being used as the setting for the Nerath world. The Keep on the Shadowfell and the town of Winterhaven are the only places of the Nentir Vale that eventually appeared in a Forgotten Realms product.