Wow, thanks everyone! Mark Chance, I will definately use your template. Sweeny, I knew I had seen a Necromancer module that featured clockwork creatures, I just couldn't remember which one. Thanks.
I'm also thinking about fun stuff like clockwork Ballistae that are activated by pressure plates or something. Maybe some sort of clockwork murder holes too. I want a fortress that keeps defending itself even though the residents are long gone. Plus, one of the characters is a dwarf fighter who comes from a family of famous clockmakers. He won't be able to resist a place like this.