This series consists of local authority case files in the P series and general and policy files in the PG series.
The files were originally raised in the Welsh Offices of the Ministry of Town and Country Planning and of the Ministry of Local Government and Planning and later the Welsh Office of the Ministry of Housing and Local Government. Following the setting up of the Welsh Office after 1964, they passed to the Town and Country Planning Division of the new department.
Under the Town and Country Planning Acts of 1944 and 1947, local planning authorities were required to survey their areas and to prepare and submit development plans. Included in the P series are submissions from all the Welsh county and county borough councils (the local planning authorities). Also included are files dealing with such functions as appeals against refusal to permit development, tree preservation orders, use of land by the armed services and post war housing development. Included in the PG series are files dealing with the setting up and administration of two national parks, the location of industry and the minutes of meetings of various Welsh industrial panels and committees. Also contained are policy and case files relating to the work of the Derelict Land Unit.
In addition to town and country planning matters generally many files concern development plans, the establishment and running of national parks within Wales and the removal of coal tips at Aberfan and elsewhere, following the disaster in 1966. The series includes a number of maps, plans and photographs.