The remains of a Cornish beam-engine house built in 1816 to pump water from Pearl shaft, Mona Mine (nprn 300167), and to pump water to other engines further uphill. The Pearl shaft (capped) is adjacent to the south of the house, the remains of the boiler house abut to the north and the base of the (now collapsed) chimney stands to the west.

(Source: Cadw scheduling description)
B.A.Malaws, RCAHMW, 02 February 2007.