Greater Manchester is a metropolitan county in North West England, with a population of 2.68 million. It encompasses one of the largest metropolitan areas in the United Kingdom and comprises ten metropolitan boroughs: Bolton, Bury, Oldham, Rochdale, Stockport, Tameside, Trafford, Wigan, and the cities of Manchester and Salford. Greater Manchester was created on 1 April 1974 as a result of the Local Government Act 1972.
Greater Manchester spans 493 square miles (1,277 km2). It is landlocked and borders Cheshire (to the south-west and south), Derbyshire (to the south-east), West Yorkshire (to the north-east), Lancashire (to the north) and Merseyside (to the west). There is a mix of high-density urban areas, suburbs, semi-rural and rural locations in Greater Manchester, but land use is mostly urban. It has a focused central business district, formed by Manchester city centre and the adjoining parts of Salford and Trafford, but Greater Manchester is also a polycentric county with ten metropolitan districts, each of which has at least one major town centre and outlying suburbs. The Greater Manchester Urban Area is the third most populous conurbation in the UK, and spans across most of the county's territory.
Greenfield is a village in the Saddleworth parish of the Metropolitan Borough of Oldham in Greater Manchester, England. It is 4 miles (6.4 km) east of Oldham, and 13 miles (21 km) east-northeast of the city of Manchester. It lies in a broad rural area amongst the South Pennines. To the east of the village Dovestone Reservoir, Chew Reservoir and Greenfield Reservoir lie within the Peak District National Park, though no part of the village itself lies within the Peak Park boundary.
Lying within the ancient county boundaries of the West Riding of Yorkshire, Greenfield is mainly situated on and around two roads in the Chew Valley in the Pennines. One of these roads is the main A635 road from Ashton-under-Lyne to Holmfirth.