The floor was cold, grey stone.  A single slab, by the look of it.  The walls were seemingly made of the same material, but they gave off a muted glow.  It was the only light source in the room.  I say walls, but I should say wall.  There was only one, circular and enclosing the whole space, about twenty feet across.  There was no obvious seam between the wall and floor, either, so perhaps the whole room was carved out of one very large rock.

The ceiling, if there was one, was out of sight, shrouded in darkness above.  Had I not felt trapped, perhaps I might have appreciated the architectural feat the room represented.  As it was, I had woken up in this place without any idea of how I had gotten here, or even where here was.  No doors were visible in the floor or wall.  If I had fallen, my injuries would be greater than the scrapes I had received from the rough floor.  Maybe I had been lowered down.  Or maybe there were doors well hidden from sight.

Whatever the case, it was clear I was not going anywhere right now.  After being awake for only a few minutes, I could feel panic rising.  Was this a prison?  Or was this just a very odd cavern I had stumbled into?  The room gave no answers, only its muted light.  I was helpless and at the mercy of my situation.  I tried to calm down, tried to distract myself.  An empty room was a poor environment in which to try, but the alternative was madness.  All I could do was sit and wait.  And hope that someone knew I was here.