This dataset comprises the boundaries of Ancient Woodland sites in Wales. Each site is categorised as either Ancient Semi Natural Woodland (ASNW), Restored Ancient Woodland Site (RAWS), Plantation on Ancient Woodland Site (PAWS) or Ancient Woodland Site of Unknown Category (AWSU). Initially all woods greater than 2 ha shown on the Ordnance Survey (OS) 1:25 000 1st Series maps surveyed between 1880 and 1960 were considered. Evidence as to which of these were ancient was provided by presence on the earlier 19th century OS 1st Edition Maps (surveyed 1805 - 1873; scale 1:63 360). The general presumption was that woodland on 1800s maps was ancient, unless there was other evidence that the wood originated between 1600AD and 1800. Supportive indications of ancient status included the wood's name, its situation in the landscape, and the nature of both the surrounding pattern of enclosure and the pattern of boundaries within the wood. Where available, field survey data such as the presence of indicator species, or other historical maps and documents were also used. In mountainous areas such as Wales the first edition Ordnance Survey 1 inch maps were hard to interpret because the heavy hatching used to indicate steep slopes tended to obscure tree symbols. Attribution statement: Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Contains Ordnance Survey Data. Ordnance Survey Licence number AC0000849444. Crown Copyright and Database Right.