The coal extraction industry has had a massive impact on the natural environment at a landscape level, the most obvious legacy of the operations being the extensive coal spoil tips apparent across the region. In recent years millions of pounds have been spent on the stabilisation and eventual reclamation of these spoil areas and their redevelopment for housing, new industry or local open spaces. In the past the potential ecological value of the tips has generally been overlooked or understated. However, old coal spoil sites are now recognised as an important habitat for a range of species and the few remaining sites in the Valleys also have cultural and community value, however general awareness of the value of these sites is low. This has resulted in a loss of site value in term of heritage, ecology, landscape and amenity and there was a need to put individual sites into a context. The former Countryside Council for Wales (CCW), which is now part of Natural Resources Wales (NRW), conducted an integrated strategic assessment of the recreational use and conservation value of heathland and associated habitats on the coal spoils of South Wales. This dataset compiles of the results of an National Vegetation Classification (NVC) survey of coal spoil habitats on 15 sites in the South Wales valleys. It contains quadrat and species data for heath, grassland, mire and associated habitats and mapped habitat polygons. The purpose of this data capture was to conduct a strategic assessment of the conservation value of coal spoil in the South Wales valleys to be used to identify important sites which require protection through the planning process and as possible use for designation of sites. It has also been used to aid in identifying action by Local Biodiversity Action Plans (LBAPs). The area covered includes South Wales valley; Torfaen, Rhondda Cynon Taf, Caerphilly and Merthyr County Borough Council (CBCs).