The Infinite Battlefield of Acheron

Acheron is made up of a multitude of enormous iron cubes floating in an airy void. Sometimes the cubes collide. Echoes of past collisions linger throughout the plane, mingling with the sounds of armies colliding. That’s the nature of Acheron: strife and war, as the spirits of fallen soldiers join in endless battle against orcs devoted to Gruumsh, and legions assembled by other warmongering gods.
The cubes that make up Acheron are pitted and scarred with cracks and dents from their many collisions and craters from their many battles. On the orderly plane of Acheron, the cubes always rust or fracture along straight lines and at right angles. Some of the cubes are only a few hundred feet on a side, but others are big enough for whole cities and kingdoms. Geometric shapes other than cubes exist, though they are rare..
Vision is normal on Acheron. The plane is lighted by a gray, fluctuating illumination that varies slightly between bright moonlight and a dark, cloudy day. Hearing is also normal, though the echo of colliding cubes and the ring of battle is always in the background.
As on all the lower planes, the River Styx flows through Acheron. The Styx flows on many of Acheron's cubes—welling up from a crater on one cube to flow many miles, then leaking down into another crater, and reappearing on another cube. Sometimes the river takes a new course over a cube face, which can result in entire cities being washed away in a tide of forgetfulness and death.
Portals to other planes are fairly common. Usually, such gates appear in the mouths of the many tunnels that riddle most of Acheron's cubes.

Objective Directional Gravity

The strength of gravity is the same as on the Material Plane, but which way is down depends on which face of the cube you're on. Walking across edges between faces can be dizzying for the inexperienced.

Inhabitants

Renegade armies filled with every sort of creature wander the faces of Acheron looking for enemy forces to fight. However, mutiny or madness soon brings down even the strongest military leader, leaving most armies without a true objective other than the destruction of other renegade armies. Sometimes armies of undead or constructs last longer, because they are able to mindlessly fulfill their last orders.
Armies that have not gone completely mad may still seek a goal, such as the defense of a realm, the procurement of provisions, the overthrow of an impostor king, or any of a hundred other causes. Unfortunately, because most of those causes were important on a plane far from Acheron, even the most steadfast armies soon lose focus and go renegade.
Acheron also holds enormous flocks of birds. Ravens, vultures, gulls, bloodhawks, and swallows tumble on the wind, sated on the carnage of the many battlefields.

Type

Dimensional plane

Location under

The Planes of Existence