I've never been happy with the default mines. I used the 'soft mines' for a while, but finally decided to treat mines as a generic term for 'industry' and developed a small 'community' tile, including a range of building and a couple small soft mines. The whole set is pretty small compared to most - seemed fit Sn00pys cities better and distract less. Also included alternate fortresses and barricades using kinboats trenches for industrial. Not sure where the pieces for the modern age came from.