[Mental note: I want to kill blogger. Grr! I've had this post freak out on my a couple times - FYI]
Here are some pictures of my first fieldstone dungeon. My build is based on approaches and ideas gleaned from two sources: Caveman on the HA boards and the build over at the Grognardia blog. My approach here is not to create whole dungeons but rather to have a rolling dungeon that can build two to five rooms at any given time. In terms of aesthetics, I didn't want a "clean" dungeon. I wanted an antiqued, dirty look with moss between stones, the odd blood splatter, and other marks that show something or someone was lived there.
I used excalibur and the three colour approach advocated by Bruce. However, I washed the entire dungeon in a thin coat of Army Painter Quickshade to both weather it and seal it at the same time. I then lightly drybrushed medium gray over all the pieces and dullcoted. I've tried take pictures using both the mircroscope and the telescope (so to speak) to show how some of the specialty pieces fit together.
I'll prpbably post more on the construction of this build but if you have specific questions feel free to let fly in the comments.