The Skeleton's Maw                                     -      N      - 
(-------------------------------------------------)     W <---(M)---> E
                                                        -      S      -

As you approach the bridge, you notice that it is not really a skeleton
at all; it is instead the likeness of a skeleton carved out of one massive
block of stone.  Cryptic runes engraved in the bridge cover it's length,
made by some unknown race which apparently abandoned these caverns centuries
ago.  From the west and northeast echo the sounds of a raging river, and to
your east, the cavern wall rises from the ground under your feet to become
the ceiling over your head.