The Dream Cave. During December 1822, miners excavating a new shaft on a hill above Wirksworth in their quest for lead ore happened upon a natural cavern, which was to become known as ‘the Dream Cave’. As the miners began to remove the infill, they uncovered the almost complete skeleton of a Woolly Rhinoceros (Coelodonta antiquitatis). Nr. Wirksworth, Derbyshire, UK.