 The mines contain a range of features including well preserved tramways, cart-roads and crane bases.The walls and pillars are studded with pick and tool marks and show evidence of the use of huge stone saws, all of which bear testimony to the variety of techniques used to extract the stone over the mine's three hundred year history.No mine abandonment plans — either of the tunnels or the caverns, known as voids — were made prior to the 1872 Mining Act.