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. Listing was begun by a provision in the Town and Country Planning Act 1947.[3] Once a building is listed, strict limitations are imposed on the modifications allowed to its structure or fittings and alterations require listed building consent.[4] In Wales, authority for listing or delisting, under the Planning (Listed Buildings and Conservation Areas) Act 1990,[5] rests with the Welsh Ministers, though these decisions are based on the recommendations of Cadw.[6] There are around 30,000 listed buildings in Wales and these are categorised into three grades: Grade I (one), II* (two star) and II (two). The highest is Grade I which denotes "buildings of exceptional interest" and makes up fewer than two per cent of the total number of listed buildings in Wales.[7]
Merthyr Tydfil County Borough has one Grade I listed building, Cyfarthfa Castle. The castle has two listing designations,[8][9] dating from the time of listing when the castle was subdivided into a museum and a school.
1824-5. Designed by Robert Lugar for ironmaster William Crawshay II. Situated in its own landscaped park overlooking the Taff Valley and site of the former Cyfarthfa Ironworks.[8][9]