The Dark Forest                                        -      N      - 
(-------------------------------------------------)     W <---(M)---> E
                                                        -      S      -

This is a very dark, dense part of the forest.  The trees grow close
together while brambles, bushes and other forest plants curl around the
trunks.  Moving here is an effort, even more so than usual due to the
oppressive darkness.  The canopy of the trees is so wide it effectively
blocks out all light from above and even seems to dim the light from your
torch.  You note eyes hiding in the darkness, glittering in the torchlight,
watching you, waiting...  
An enraged she-troll smashes through the forest!
A greenish-skinned, heavily muscled humanoid stands here.
    You sense a hidden life form in the area.
A huge, greenish, hairy humanoid creature shambles through the forest.