Please do not go to the given coordinates! I have no idea what trouble you'd get into there, but even if it were minimal, why bother, since the cache is not hidden there. To receive the coordinates for the actual hiding spot of this cache, please solve the attached crossword puzzle, then enter a set of eight words (alphabetized, with no spaces) into Certitude. What words, you ask? Well now, that's what makes this a puzzle, doesn't it?
Certitude’s at 0-60, so it’s time for another couple of clues. Black holes, I believe the astronomers say, are known by their effects, because they can’t exactly be seen. Nonetheless, we call them black. You have only the crossword before you: where are its black “holes”?
You can validate your puzzle solution with certitude.
Nf lbh'ir thrffrq, gvzr ba gur Jro vf erdhvfvgr gb gur fbyhgvba (rkprcg sbe gur rkgenbeqvanel). Irel bsgra jr jrer fhecevfrq ol jung jr yrnearq. Rayvtugrarq, rira. Fgrnygu ng TM, bs pbhefr.