Plumbley Colliery, which includes the Seldom Seen engine house, lies in woodland 1 kilometre north west of Eckington. The monument includes the ruined buildings, earthworks and buried remains of Plumley Colliery, including the engine house, fan house, coke ovens and conical tips. Plumbley Colliery was operationg by 1875. The colliery complex had reached its full extent by 1897 and was disused by 1914. The Seldom Seen engine house, in the northern part of the site, stands to a height of 12-15 metres. The brick-built engine house is unusually large, with walls pierced by round arched and square openings. Some roof and floor timbers survive, one moulded and one bearing a pulley, protrude from the south wall. Within, thick bearing walls for an indoor beam engine survive. The engine is thought to have been used for both winding and pumping in the shaft, and its boiler was located in a brick chamber built against the west wall of the engine house, the ruined walls of which survive. To the east of the engine house are a number of earthworks believed to represent coke ovens. Immediately north of the engine house is a range of spoil heaps, at least two of which are characteristically conical in form. A brick-built adit, partially visible beneath later deposits, is cut into the slope, south of the engine house where the land rises. West of this are the ruined remains of a Guibal fan house. South of the fan house and adit, at the top of the slope, a broad footpath follows the east-west line of a former railway which served the colliery, and remains of the railway are expected to survive beneath it. To the south of the path, further earthworks and ruins remain visible in woodland including the remains of a second engine house with intact engine bed, large well-preserved earthworks representing reservoirs shown on the Ordnance Survey map of 1897 and also the remains of several shafts, some large and collapsed. Scheduled.