The Interdimensional Void

The Interdimensional Void is a really strange area located in the Backrooms.

Description
An Interdimensional Void is the area in between every single level in the Backrooms.

Extra universal space is the term for the empty void of pure vacuum (or, in some interpretations, nothing at all) filling multiverses in between the universes inside. It is essentially a smaller-scale version of The Outside. Some methods of travelling between levels involve going through this space. It has an arbitrary number of dimensions in both space and time.

This "space" does not always have to exist. Levels can be constructed so that some are in the same spatial location but overlapped on top of each other, and there are undoubtedly many other ways to arrange a huge or infinite number of Levels without needing a space beyond it. In fact, not all levels of the Backrooms are surrounded by this. You can "float" in this level.

Entrances and Exits
Unsuccessful no-clippings can sometimes send you here. To exit, the best bet is to somehow manage to clip inside a level.