The Unseen Grotto of Night's Embrace is basically a small, floating mountain riddled with damp caves and maze-like passages carved by joint effort of the twisting, flowing geomantic energies focused there, and good old H2O. Though it floats on the surface of the western seas, it does not drift, anchored as it is by it's own magic. The grotto is completely undetectable when outside of it, though once inside its borders its true nature begins to show quite clearly: Namely, it gets REALLY dark, really fast. This sudden, unnatural night is so complete that even the moon and stars give up and go home, and light sources that are brought are sharply limited in range. Bring a torch. Or ten.