Some inspirational description of architecture for today:
"Dark, glassy, jointless stone slid past. "My god!" He could see into the wall. He saw bones, fragments of bones, bodies, pieces of bodies, all suspended as if floating in the night. As Raven turned toward the gate, he saw a staring face. "What kind of place is this?""
- Glen Cook, Shadows Linger, p. 57
I don't do horror gaming, but I do put unpleasant, horrible evil into my games. I just tend to deal with it more matter-of-fact. Here is total evil, something wrong on every level, now put your big boy pants on and do something about it. Or not.
I get a lot of my descriptions of banal horror from history and from fantasy - Glen Cook is right at the top of that for me.