terraining a dungeon/prison level

I am having some problems terraining a dungeon level I am making. The level is supposed to be an unground orcish prison that the hero must escape from. My main problem is trying to make it look interesting.

The rooms are fairly easy, as I can place furnishings etc, but I have many long corridors. Since its a manmade area I cant really have too many changes in hill height and while I have changed the floor tiles to match the area the corridors look boring. The main doodads I have found that can be used are chains (chains hanging from the wall) and torches. Other things like skeletons, skulls on sticks etc look out of place since the area is supposed to be an occupied dungeon.

Does anyone have any ideas about ways I can improve this, either with tiles, doodads or other methods?

Thanks,
SheepOfDoom

In the dungeon campaign levels (i.e. rescuing Illidan, pursuing the oracle), they do things like lining the walls with another wall-like layer of bars. It doesn't change the map layout but it does feel pretty derned prisony.

Also, breaking up your corridors might help them become more interesting. For example, you could put guard posts every now and then, making the corridor widen into a small room and then narrow back into a corridor again.

And of course, if you're into modelling, you can alter some of the doodads into applicable things. A good use might be to make a hanging skeleton into a hanging peasant, or whatnot.

Good luck. I'm fond of the dungeon tilesets, as they're so rarely used, and even then so rarely cool-looking.