The Void

To call The Void a place of nothing is an understatement. It would apply that there simply isn't anything present, but in reality, it is the opposite of something. The centre of the plane is a black star that is constantly eating away at the swirling traces of space around it. Those far enough away to be able to return see entire nebulae being sucked into the darkness.
This isn't a black hole as Earth scientists know them. It is a bleeding gash in reality itself and the universe leaks out through it. Around it is the vacuum of space. There might be planets around the distant, dying, stars but if so, no one has visited them.

Settlements

There are a few dozen settlements in cramped space stations orbiting the black star. They are generally not welcoming of strangers and consider throwing them out of an airlock to be a fair punishment for interfering too much. That said, they're willing to negotiate for any outside resources.

Localized Phenomena

There is a sort of gravity used by the stations that exist here. The station is constantly pushing to stay away from the black star and as a result, the side towards the star acts as a "down".
Everything in The Void slowly but surely breaks down. The structure of materials and the cohesion of cells fall apart. Ageing is unpredictable but quicker closer to the dark sun you get. There are legends about those who have managed to use the process to act in the reverse - restoring their youth. But no one seems able to point to an actual example of this

Natural Resources

The debris being pulled towards the black star contains every type of material imaginable. Those stupid enough to try to salvage some can bring back a fortune if they survive. The closer to the star you get, the easier to is to collect and the more strange effects it will have on you.

History

Some say that The Void is actually a defence against the growth of the Thicket of Thorns. Those who believe this often point to the Elohim as likely culprits. The angels have refused to even entertain such a conspiracy theory in public.

Type

Dimensional plane