Early 19th century – 1890. The Minera Mountain Company (1877-1913) incorporated the later workings of South Minera and Park.
Western Shaft (SJ25405140) stands to the west of the road up to Esclusham Mountain from Minera. All the mine buildings are destroyed and difficult to interpret. It is substantially capped, with the remains of its engine house adjacent. The entire site is in a very poor state of preservation. Several smaller shafts surround the main shaft. The Park Mines were drained by an extension of the Minera Upper Day Level from Speedwell Shaft. An incline connected the dressing floors with Hill Shaft. Although basal engine mountings remain in situ at SJ25405140, the features of the engine house are almost wholly destroyed. The sett is cut by the Gwyter Siani Leat, which runs downhill from the moorland above Wynnstay sett, contouring the hillsides of Esclusham Mountain to the Minera Mines in the valley. An extensive area of spoil heaps and dressing floor waste lie alongside modern building waste.
Hill shaft lies approx 300m uphill to the south-east of Western Shaft at SJ25605210. The shaft, now substantially capped was sunk prior to 1850. The site remains as extensive spoil heaps with the demolished remains of an engine house, south of the shaft. A large shaft lies to the south of this area at SJ25605100. The Park Mines were drained by the Minera Upper Day Level. An incline appears to run downhill to Western Shaft and the dressing floor areas. There is evidence that a large whim shaft, which has been cut in half, was formerly operating the engine shaft. The site was apparently re-equipped with the steam pumping engine in 1858. The shallower shafts had whims. The seating blocks of the engine are barely visible. The pumping engine house appears to have its boiler house and chimney to the south. The remains of two pools are to the west and east of the engine house. The dressing floor areas were on the Western Shaft site (PRN 104373). The remains of ore bins can be located on the side of the spoil tips by the destroyed engine house. The smithy stood at SJ26555110.
New Shaft (SJ26105085) was sunk in 1865 to 225yd level on the eastern end of the Park Vein. The Park mines worked until the 1890s. The wide Engine Shaft is substantially capped at SJ26135084. The mines were drained by an extension of the Minera Upper Day Level from Speedwells Shaft, being some 700ft below New Shaft. A substantial track runs uphill from Hill Shaft for a quarter of a mile before reaching the entrance to New Shaft. The substantial trackway suggests the use of horse and carts for transporting ore. The remains of the housing for a horizontal winding engine stand at SJ26102585, with some of the engine mountings and wheelpit bolts still in situ. The boiler house foundations appear to be adjoined to it on its southern side. The remains of a second engine house related to processing stand to the south-east of the shaft at SJ26165830. This must postdate the shaft, as it does not show on the plan of the three Park Shafts c1867 deposited in CRO, Hawarden. The CRO plan has the engine house in an enclosure to the east of the shaft. Two engines were recorded on the site in 1899. The pond illustrated on the early maps at SJ26015086 running northwards still holds water and a further pool of water lies to the north of the entrance track at SJ20505089.
The processing area to the west of New Shaft at SJ26155083 remains as a large areas of jigger tailings beyond the shaft on the south-eastern perimeters of the sett. The area is surrounded by large spoil mounds to the north and west. The engine house could have housed a crusher. The reservoir/pool at SJ26065081 would provide water for the washing and separating of ore. The enclosure illustrated on the plan could be a line of ore bins, which can be identified to the west of the shaft. The schedule of buildings on the mine sett in 1899 lists two engine houses, winding and a compressor, a cabin, smithy and shed; all being in good order. The basal stone foundations of a building at SJ26085830 could be a store or a smithy.