Crimson’s Creative Challenge #234 Light of the world

This stark, six-sided monstrosity

is used as a bird observatory

but the rooftop cupola gives a clue

as to the job it was built to do

for every night and on foggy days

a bright light would shine out through the haze

this nightly shining man-made moon

whose bright beams pierce the the dark and gloom

warning sailors on vessels out at sea

you had better not come too close to me

for beneath the cliffs on which I stand

lie unseen rocks and shifting sands

so my advice is to turn away

and you will live to sail on another day