A Smooth Tunnel                                        -      N      - 
(-------------------------------------------------)     - <---(M)---> E
                                                        -      S      -

As you enter this small, cramped tunnel, the sound of running water
echoes in from the north, and the sound of a shuffling..  Creatures can be
heard from the south.  The walls of this tunnel have been worn smooth by
ages of what had apparently been an underwater stream, which has over the
years changed its path.