White Castle lies between Abergavenny and Monmouth in the Welsh Marches. Its origins lie in the Norman Conquest of the region, but the earliest stone remains date to the 12th century. It was placed in State Guardianship in 1922.
C.A. Ralegh Radford prepared the guidebook for White Castle in 1934 (along with the other two castles of ‘The Three Castles’: Grosmont and Skenfrith). The DOE Blue Guide is partially bilingual. The title page (but not the cover) gives the English and Welsh titles of the site: White Castle / Castell Gwyn, and it was prepared by the DOE on behalf of the Secretary of State for Wales. The guide is in two main parts: history and description. However it is introduced with a short summary in Welsh (pp. 5–7). There is a foldout plan inside the back cover.
The 1991 Cadw guide for the Three Castles was prepared by Jeremy K. Knight.