There is a salt mine in Kansas too, 600 feet underground. Neat tour. I seem to recall seeing a Cylon from the original Battlestar Galactica down there. https

There is a salt mine in Kansas too, 600 feet underground. Neat tour. I seem to recall seeing a Cylon from the original Battlestar Galactica down there. https://www.underkansas.org/ https://www.underkansas.org/ Also a yearly midnight ride through limestone caverns, though I have not done that one yet.