Have humans ever seen a black hole?

Most famously, black holes were predicted by Einstein's theory of general relativity, which showed that when a massive star dies, it leaves behind a small, dense remnant core. If the core's mass .... January 5, 2017, Deepest X-ray Image Ever Reveals Black Hole Treasure Trove (Chandra Deep Field South). read more

However, should we see a black hole in person, we would probably be past the event horizon and we would essentially be erased from history. So, again, we cannot directly see a black hole. We can only see evidence of one. read more

Of course we have not seen the actual event horizon of a black hole. This is because black holes themselves are to small, to far away, and have to much stuff going on around them to actually see through a telescope. But as you have said; yes, we do have photographs of structures that appear going over/behind/around/into black holes. read more