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

The canyon is at it's deepest here.  There is no sunlight that hits the
bottom at all.  One reason is that on the surface and to the west is the
summit of the mountain range that goes through the desert.  It is also much
colder down here than in other parts of the canyon.  
A large boulder crashes down from above and shatters directly behind you!