Heya. These look pretty good. Those are some pretty serious piles of dead people. There's some fungus (violet?) that eats corpses or blood or something. Might think about having some of that nearby if you do something similar in the future. Think maybe the 3.5e Lords of Madness book had something about a beholder den with some of this in there...eating the runoff from his slaughters. Gods, I love that book.
Anyway, for next time, you might want to think about making the surrounding rock a darker for that Underdarktm feel. That would be a simple change, really...just replace the texture and you're done. I'm always torn about how to map places that should be dark...you have to make things light enough so that the viewer can see what's going on in your map but it's also good to imply the lighting situation if possible. Here you could have maybe made the whole thing darker but used the ambient light from luminescent fungus and a couple of torches to bring out the visible detail for the viewer.
Looking forward to seeing more maps from you. Have some rep for posting a map your first time out!
edit: Argh. Rep tool window is disappearing on me again. I'll hit you back when I can.