|The following is based on developer test content cut from Fallout: New Vegas.|
A simple empty metal room with no doors or lighting. There are four other identical rooms which must be no-clipped in to access, and one larger, equally empty room. Another room has three NPCs, which appear to be Lily Bowen when she was a human, and her two grandchildren, Becky and Jimmy.
The sound of something knocking on metal can be heard in this test cell. The NPCs make the same sound when one gets too close.
Cell for Dead "Void Creatures" appears only in the game files of Fallout: New Vegas, but should not be considered canon because it is a test cell.