Since there's some discussion about non-space/times, I was wondering about how we'd treat something like The Void from Doctor Who.
The Void exists between all universes in Doctor Who. It's otherwise a typical 'never-space' fictional void, composed of
literally nothing (including space-time) and containing almost nothing.
What stands out are two aspects of the Void:
Firstly, the Time Vortex and the timeless/spaceless void at the end of reality are almost always referred to as no/non reality, space, time, etc. The Void is explicitly beyond them, and is described as un reality, space, time, etc, meaning it's simultaneously
immeasurably huge and
tiny. This suggests that un- means both 'opposite/negative' and 'non' reality, in this case.
Secondly, while The Void is called 'The Void between universes', it also exists
everywhere in universes, and certain races can access it for space-time travel within a single continuum.