Nerath

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

Locations
The only known locations of this world were a unnamed continent where the Empire of Nerath once was located, with places such as the Nentir Vale and the Elsir Vale; a great island named Kelarnil ; and a continent named Selduria.

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.

Relative time
By the year 1479 DR in the Realms, it has been 90 years since the fall of the Empire of Nerath in this world.

This is supported by the novels of the Abyssal Plague, as well as the adventure The Elder Elemental Eye.

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