A Large Conveyor Belt                                  -      N      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      S      -

You hop on the slow moving conveyor belt and see where it leads.  The
belt moves so slowly that you will have no problem in going back.  Rocks
bounce all over the place, several coming close to your head.  Be
careful!!!  Ahead you see the conveyor belt turning to the left.
A blacksmith apprentice wanders around busily working the forge.
You dodge out of the way of a large stalactite that is dislodged from the ceiling!