Shadowfell

Shadowfell is home to The Raven Queen and since the agreement of from all gods and Asmodeus, is the place mortal souls are sent first to be judged. She can deliver you a reward and send you to be with your deity's ideal layer of Mount Celestia, she can punish you and force you into the ranks of the Nine Hells, but she will mostly do what she often decides, which is to send you soul away on a journey through the empty and cold barren hills of Shadowfell.

Shadowfell is a place that's always cast in shadow, clouds overhead over the sky as light tries to break through but only reveals a few cracks. There are very little surface features, but mostly what you see is crags and mounds of dust. Many mortal souls find being trapped there fairly unpleasant and an empty experience which forces them to reflect upon their choices.