This book is based on several years of author's fieldwork in the valleys of the Black Mountains in South East Wales. Hodges had personal knowledge of the area having worked there in his professional capacity as a drystone waller. The aim of the fieldwork was to locate all the sites of derelict stone buildings within the designated upland study area of approximately 140 square kilometres. Initial research indicated that the area had not been previously surveyed to any great extent and the presence of derelict stone buildings that existed in the valleys was not a characteristic of the surrounding lower terrain. Using a combination of documentary evidence and fieldwork, a total of 549 potential sites were identified comprising houses, barns, other ancillary buildings and sheepfolds; 499 separate structures were located on the ground. Following a specially devised protocol at each site, information regarding masonry, modes of construction and extant features was recorded in both tabular and photographic forms.