Ice House                                              NW     N      - 
(-------------------------------------------------)     W <---(M)---> -
                                                        -      -      -

Although the air outside is cool, the temperature drops significantly as
stones, mortared tightly together to hold the air inside.  Huge blocks of
ice are stacked all through the room, and you can see that a variety of
different foods are stored here.  You imagine that it must be rather
expensive to replace the ice as it melts, and wonder if there might be a
more efficient way to keep food cold.  
A worker is busy chipping large chunks of ice up into manageble portions.
A worker is busy chipping large chunks of ice up into manageble portions.