A Tiny Islet                                           -      N      - 
(-------------------------------------------------)     W <---(M)---> -
                                                        -      S      -

You are standing atop a small pile of rocks in the corner of a massive
subterranean cavern of some sort.  A huge underground lake surrounds the bit
of dry land you occupy, and it is impossible to see the other edge of the
water through the darkness.  The wall of the cavern to the east is worn and
cracked, and it looks climbable.