A Subterranean Observatory

 A Subterranean Observatory                             -      -      -
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  As your eyes adjust to the dim lighting of this room, you realize you
have just entered the observatory.  At first, you wonder why anyone would
build one so far beneath the earth, but then you begin to take in your
surroundings.  There appear to be clouds all along the floor of this room
but you discover they are chairs and couches, though as billowy and cool as
wisps of air.  They invite you to sit down and engage in quiet conversation,
or to reflect on things in your own mind.  Encircling the room's ceiling is
a walkway that seems to provide closer viewing of it.  But the ceiling
itself seems divinely inspired in its origins.  Massive black marble columns
support the black dome, made of a material you do not recognize.  Upon this
domed canvas, magical lights representing stars move in a rotating dance. 
Your eyes are drawn to the brilliant constellations above you.  A single
star at the center of this interplay radiates especially brightly beyond all
its companions, and the name "Polaris" glows next to it, filling your heart
with pride and hope.  In the center of the room is a marble dais covered in
knobs and buttons, which you assume controls the dance above.  Next to these
controls lies an obsidian tablet with a pair of phrases inscribed into it. 
Curious, you utter the first and are stunned as the to transparency,
allowing an unobstructed view of the sky beyond.  You quickly walk over the
edge of the walkway and look down into an infinite expanse of stars that
completely surround you!  Recovering from the shock, you try the other
phrase and watch as the dome and earth materialize and the planetarium's
light show resumes.  Northstar must be home to truly powerful magi indeed if
they are able to craft a room such as this!