In the United Kingdom, the term listed building refers to a building or other structure officially designated as being of special architectural, historical, or cultural significance; Grade I structures are those considered to be "buildings of exceptional interest". Listing was begun by a provision in the Town and Country Planning Act 1947. Once listed, strict limitations are imposed on the modifications allowed to a building's structure or fittings. In Wales, the authority for listing under the Planning (Listed Buildings and Conservation Areas) Act 1990 rests with Cadw.
|Name||Location||Date Listed||Grid Ref.[note 1]
|Function||Notes||HB No[note 2]||Image|
|Balance tower, Blaenavon Ironworks||Blaenavon||2 September 1995||Lift||At N end of site. Hydraulic lift to raise iron and raw materials in trams.||15292|
|Blast furnaces, Blaenavon Ironworks||Blaenavon||2 September 1995||Blast furnace||Three extant furnaces and the remains of others, stand in a row on the north-west side of the furnace yard, behind the cast houses.||15294|
|Cast house and foundry, Blaenavon Ironworks||Blaenavon||2 September 1995||Foundry||To NW of site. The extant cast house to furnace No 1.||15296|
Media related to Grade I listed buildings in Torfaen at Wikimedia Commons