|The following is based on developer test content cut from Fallout: New Vegas and has not been confirmed by canon sources.|
A simple empty metal room with no doors or lighting. There are four other identical rooms which must be no-clipped into to access, and one larger, equally empty room. Another room has 3 NPCs, which could 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 keep making the same sound when you get to closer.