A Noisy Tunnel                                         -      N      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      S      -

The tunnel walls are slick with gooey damp moss and slime, torches hiss
and flicker quietly throwing a dim light on the area.  The tunnel appears to
be quite clean and well traveled, giving evidence it is a main access tunnel
for something.  A deafening sound of hammers hitting stone echos throughout
this area, muffling the shouts of workers further along in the tunnel.