The Tube to Atlantis                                   -      -      - 
(-------------------------------------------------)     - <---(M)---> E
                                                        -      -      -

The dome of Atlantis bubbles slightly at each step, sending a shimmer
through the images below.  Mermen look up occasionally, but seem not to
notice anything out of the ordinary.  Walking apparently with no floor below
causes most stomachs to turn uneasily, the ocean floor some fifty feet below
looks even harder from this distance.  Down leads to the Center Square of
Atlantis, the city of fable and legend.