Engine House at Approx 50m West of Wheal Bush Farmhouse,Killifreth Mine.

The engine house located approximately 50 meters west of Wheal Bush Farmhouse at Killifreth Mine is a ruin dating from the mid to late 19th century. It is primarily constructed from killas rubble, featuring granite quoins, jambstones, and bonding stones, with dressed coursed granite facing on the southeast wall. A round, two-stage chimney is positioned at the north corner, which has round brick arches over its openings and a brick upper stage. The building originally had a gable-ended roof but is now roofless and floorless. It has a rectangular single-cell plan, with a thicker bob wall to the southeast and the round chimney adjoining the north corner. Originally, the structure was three storeys high, and the walls remain mostly intact, except for a framed and weather-boarded wall and gable end over the bob wall. The first and second floors on the northwest side still show the outer frames of the original windows. A brick collar divides the stages of the chimney. This engine house was likely used for operating a whim and is part of the Unity Wood and Killifreth Mines, which were reopened in 1865.