Canyon of Despair                                      -      N      - 
(-------------------------------------------------)     W <---(M)---> -
                                                        -      -      -

The canyon is starting to become more narrow here.  It is still very deep
and far from the surface but the distance between rock walls is shrinking. 
Perhaps it is getting close to the end of the canyon.  To the west you see a
large cave that cuts through the mountains.  
A large boulder crashes down from above and shatters directly behind you!