The Mother Dragon's Flueway                            NW     -     NE 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      S      -

Descending into the inhospitable interior of the volcano, it seems like
nothing could possibly survive down there but the most rugged and extreme
beings.  It looks as though something does, or used to; small holes have
been chipped into the ceiling, allowing smoke and natural gases to escape
through them and preventing this flueway to become as asphyxiating as it
could be.  Humans' jawbones are planted in rows in the loose stone ground,
oriented parallel to the walkway that leads ever-deeper into the fiery
lavaways.