Knap Down mine is an ancient silver-leadworking. Shafts and adits surround silver mines farm. The site was reopened 1836 and worked until 1873. Some prospecting occurred 1890s & 1927. The site also contains the remains of engine house and chimney. These are built from stone rubble with brick capping to the chimney. They were built in1843. The engine house is of a rectangular plan, with a narrow semi-circular arched opening and rear wall incorporating tall circular chimney shaft.