The Forest of Dean is a geographical, historical and cultural region in the western part of the county of Gloucestershire, England. It forms a roughly triangular plateau bounded by the River Wye to the west and northwest, Herefordshire to the north, the River Severn to the south, and the City of Gloucester to the east.
The area is characterised by more than 110 square kilometres (42 sq mi) of mixed woodland, one of the surviving ancient woodlands in England. A large area was reserved for royal hunting before 1066, and remained as the second largest crown forest in England, after the New Forest. Although the name is used loosely to refer to the part of Gloucestershire between the Severn and Wye, the Forest of Dean proper has covered a much smaller area since the Middle Ages. In 1327, it was defined to cover only the royal demesne and parts of parishes within the hundred of St Briavels,and after 1668 comprised the royal demesne only. The Forest proper is within the civil parishes of West Dean, Lydbrook, Cinderford, Ruspidge, and Drybrook, together with a strip of land in the parish of English Bicknor.
Traditionally the main sources of work have been forestry – including charcoal production – iron working and coal mining. Archaeological studies have dated the earliest use of coal to Roman times for domestic heating and industrial processes such as the preparation of iron ore]
The area gives its name to the local government district, Forest of Dean, and a parliamentary constituency, both of which cover wider areas than the historic Forest. The administrative centre of the local authority is Coleford, one of the main towns in the historic Forest area, together with Cinderford and Lydney.