Gamallt lead mine (nprn 537495) is recorded in 1834 but work had ceased by the time of the 1891 OS map. The mine has a rock-cut entrance, 1.5m wide and 1.2m high, but its portal is a segmental stone arch. There is much debris in the entrance so the underground extent of the mine is unknown. It is approached by a deep cutting 9m long NW-SE, the SW side of which is rock-cut. The NE side is bound by a drystone retaining wall, 1.6m high. The mine is one of the 'Trial shafts' marked on the 1891 OS map.
Recorded as part of RCAHMW Uplands Initiative Project, W B Horton, H & H, 08/01/2014.