Squire James
Explorer
Regarding the RtToEE comment, well dwarves dig a lot. They were probably following that vein of mithril when they unearthed the (insert nasty uber-monster here). I don't think mineral veins normally run straight, so there was a profit motive for digging those strange passages.
Old dwarven mines make excellent Citadels of Evil (tm), especially depleted ones.
Old dwarven mines make excellent Citadels of Evil (tm), especially depleted ones.