See also: Charlestown United. Vertical wolfram (tungsten) lode running from north to south across Castle-an-Dinas Hill and passing through the center of the hillfort of the same name. The mine features a cluster of buildings located at South Shaft, which was sunk to a depth of 650 feet in 1945. Additionally, there are open stopes and four levels on the north side of the hill.

Within the hill’s core lies a granite cupola, and the ore diminishes as it enters this rock. The mine operated intermittently during the First and Second World Wars, albeit on a limited scale. However, its primary period of operation was from 1945 to 1958, during which approximately 3,000 tons of wolfram were produced.