Polkemmet deep mine coal pit closed around the time of the last miners' strike in 1984. The only evidence remaining is a few miners' cottages and houses, which the National Coal Board (NCB) had sold some time before the closures. A steam engine used to pull the coal wagons is on display in the local Polkemmet Country Park, formerly the private estate of the local land owning Baillie dynasty. Several other mines were dotted around the surrounding area, including the Benhar pits (Eastfield) to the west side of Harthill. These closed some years prior to the 1984 miners' strike. The Benhar pits were also very important in Harthill and Eastfield's socio-economic development. Harthill, Eastfield and Greenrigg form something of a single village entity now, but each retains its independent close-knit identity.