It's an obvious thing to say that the world is constantly changing, but it's true. There are a lot of places that can be singled out for their beauty or for their historical importance, and many of those places are threatened, either by geopolitical situations, climate change, human recklessness, or simply bad luck. You might be thinking that all of these locations are in nature and are under some kind of threat, but that's not the case! There are also some important and historic man-made structures that are past their prime.
And that's also the problem with lists like these. If these locations are pointed out and tons of people begin to visit them, that may actually make the situation worse. But, then again, if tourism dollars are used appropriately, the influx of new visitors can generate revenues that could be used for upkeep and preservation. By visiting these destinations, you can up their profile for future generations. Or, if you're more of the selfish type, you can boast that you were one of the last humans to see it in person. Regardless, here are some places to see, appreciate, and to sing their praises to other people before they're gone.