Clangor

Clangor, also known as Acheron, is a plane of eternal battle. Armies of goblin and kobold petitioners, often led by barghests, clash in struggle, only to be resurrected the following dawn and start the battle again, over and over. It is the home plane of Hruggek, Kurtulmak and Maglubiyet.

Hruggek resides in Hruggekolohk, a warren of caves, inhabited by small villages of hobgoblin petitioners, waging war with the tactics of ambush.

Kurtulmak lives in another warren of caves, Draukari. The caves are narrow, short, muddy, and so twisted that it is very easy to get lost and get ambushed by an angry tribe of kobolds.

Maglubiyet resides in a fort called Grashmog, the Hearth of Battle. Grashmog serves as a temple and training camp for clerics and warriors. The most feared ones are the Steelbiters, respected for their bond with the fiendish winter wolf mounts.

Layers
Avalas, also called the Battleplains, is the location of the orc realm of Nishrek and the goblin realm of Clangor. Bane's realm, the Black Bastion, is also on Avalas. Gilgeam's realm Zigguraxus existed here until that god's death.
 * Layer 1: Avalas

Laduguer's realm Hammergrim is here.
 * Layer 2: Thuldanin

No native life but blocks of many regular shapes such as hexagons, octagons, etc.
 * Layer 3: Tintibulus

No blocks but razor-thin squares of hard black matter move and collide in and endless sky.
 * Layer 4: Ocanthus