Lava Flow                                              -      -     NE 
(-------------------------------------------------)     - <---(M)---> -
                                                        SW     -      -

You are floating in the middle of a massive lava flow.  Flames leap up
out of the lava and the searing heat of this place is simply unbearable. 
Lava is coming out of vents in the sides of the cavern, and low rumbling can
be heard from deep within the depths.