I've always found this stuff to be interesting on a variety of levels. What happens when maintenance stops? What state did they leave things? In the cases where you have before and after shots - or multiple visits spread out over a long time - it can be even more interesting to see how things turn out.
If anyone else wants to see more of this kind of thing, I've spent a lot of time looking at places on the Detroit Urbex site.
I'm sure there are some other good explorations out there, and I hope this thread turns up a couple other hidden gems that don't pop right up on a Google search.