The Fairplay Mine boasts the most extensive remains of a Cornish underbeam engine house, situated above a well-constructed masonry shaft approximately 350 feet deep. These structures are remarkably preserved, standing up to about 15 feet above ground level. While the exact date of construction for the engine house is uncertain, sinking of the deep pit seems to have commenced around 1856. Roughly 100 yards to the east lie the filled-in remnants of an air shaft, featuring a draught opening or flue that connects the shaft to the base of an associated ventilation chimney, complete with a hearth. These features were conserved in 1980 and currently stand at about 6 feet high. South of the shafts, there are three small reservoir ponds originally used for boiler water, now serving as nature reserves. The primary aim of the venture was likely the exploitation of iron ore within the Drybrook Sandstone or Crease Limestone, although there is little evidence of significant production. The mine machinery was sold off in 1907.