Black holes (also known as a "singularity") are one of Nature's most peculiar phenomena. Nothing in the entire Universe itself can compare to the immensity and the strangeness of the singularity. That such a thing could even exist was debated for a long time. But, yet, despite the seeming impossibility of it all, we have seen evidence for the presence of black holes!
So, humour me for a moment, and imagine, if you will, the following:
Imagine a star a thousand times heavier than our Sun collapsing and getting squeezed into a point no wider than a few kilometres. Now, imagine that point of mass being so dense that nothing can escape its gravitational attraction. Next, imagine a region of space where not even light, the fastest entity in the Universe, cannot get out off. Imagine an area where we can learn nothing about, because every thing that goes it will never return to our reality: the Universe's ultimate Black Box.
If you can imagine such a thing, then you have understood why a black hole is so fascinating. But, that's not all...
Imagine if you were suddenly teleported to the edge of a black hole. The gravitational force there is immense: a small increase in distance from the centre of the hole means a huge difference in the force tugging on you. Your feet will experience a force much higher than your head. The result? You will be stretched... pulled into a long thin string by the difference in the forces, much like a rubber band... or a strand of spaghetti. And, indeed, you will be spaghettified (and I'm not kidding, that's the actual scientific term).
But, perhaps you don't like imagining such a morbid ending to your life. That's OK, someone has imagined and sketched it out for you. You just need to go to the GZ to get that sinking feeling of having one's life sucked down the drain. Oh, and you know, how they say that just before you die, you see your whole life flash in front of you? Well, since time moves incredibly slowly near a black hole, that will probably happen in slo-mo, and get to relive every single moment. A comforting thought, isn't it?
Alright, enough rambling... at the GZ, you'll find a sculpture appropriately titled "Black Hole". Looking ahead, you'll find a green space. Search the area for something that blends in. The high Difficulty rating reflects the high muggle activity in the area, and you would do well to practice stealth. Please return the cache EXACTLY as you found it, and remember to close the "cover" tightly. Good luck and happy hunting!