Here's a couple of mine.
I scratch built this mostly from illustration board, paper and different thickness of card stock. I scratch built the tower from brass.
These two are built from plaster castings I made using Linka brick molds.
This is build from all sorts of materials and it isn't finished yet. I'm not sure when I'll get back to work on it.
I try to take a lot of pictures while I'm building. If anybody is interested they're here: http://public.fotki.com/DaveInTheHat/davetown/