Features the most extensive remains of a Cornish underbeam engine house built over a finely constructed masonry shaft approximately 350 feet deep. The engine house walls stand up to about 15 feet above ground. About 100 yards east of the main shaft are the filled-in remains of an air shaft with a flue connecting to a ventilation chimney and hearth, conserved at about 6 feet high. South of the shafts lie three small reservoir ponds originally used for boiler water, now serving as a nature reserve.

The sinking of the deep pit at Fairplay Mine likely began around 1856, targeting iron ore deposits in the Crease Limestone or Drybrook Sandstone. The mine saw limited production, and its machinery was sold off in 1907, marking the end of its operation. The nearby Land Pit was also part of the mining complex but is now filled. Conservation work in 1980 preserved several ventilation features.