Subspace Realms

Subspace realms are areas of anomalous geometry and location existing between the existential universe and Null. The majority of subspace realms have broken off of greater realms (most commonly the existential universe) in the past. These realms are frequently of non-Euclidean geometry, and their borders may overlap in static or changing dimensional gateways to other spaces.

Documented Subspace Realms
The Distant Shore

The Twilight Valley

The Reef

The Astral Plane