My son has been going to various appointments at Children's Hospital of Buffalo for all of his 18 years. The hospital is short on space, so a few of the clinics are in the basement, among them, the lab that makes his AFOs (leg braces).
The basement is a series of winding corridors. Pipes and wires clutter every inch of the ceiling. The hospital staff stack bags of garbage up along the walls. You can hear the banging and clanging from the hospital laundry. I imagine there's more than a few critters skulking around the basement.
We happened to take a wrong turn after his appointment one time and got turned around. We wandered for a bit before someone pointed us in the right direction. Both he and I remarked that the basement would make a wonderful setting for a horror story.
I'm using what I saw as the basis for a sequence in The Gray Men, Book Two. One of my characters has been locked in a rather unpleasant basement room (the hospital in my story is abandoned) and she's not alone. I think it would be a horrible fate to be locked in a winding, twisty basement, especially after dark when few people are around. Pretty much anything the writer sees can be fodder for a story. With horror writers, it's always about imagining the worst happening and then dumping that on your characters.