Dungeon Keeper 2 is a late 90's game that was the first game I played with something similar to voxel mining. I still enjoy the game.
Here are some blueprints I made for Dungeon keeper a while back. I started before there was even rotatable blueprints that had blocks. So I didn't really have a way to upload all the stuff at once without zipping them and sharing a link here. But now I can at least upload most of it except the wall tops. The wall tops will be zipped and you can find them at the bottom. Hopefully more furniture to come. But right now I'm still working on a MPD map (My Pet Dungeon is a gamemode in DK2 that is similar to sandbox and isn't the main campaign)
The reason I uploaded the wall tops was to make it easier to create a more accurate dungeon similar to DK2.
Download Link (Dropbox) 6.2 MB: Dungeon Keeper 2 Wall Tops