This thesis explores the richness of Devon’s antiquarians’ records covering the period from the 15th century through to the early 20th century, and reveals the wealth of information that these archives contain about archaeological sites and medieval buildings that have since been lost. The lives of the Devon antiquarians themselves, how the carried out their research, and the unpublished and published material they have left us, are all reviewed. Of particular importance are unpublished questionnaires, journals, diaries, notebooks and commonplace books which together provide an untapped resource of information on lost and damaged archaeological sites. When assessing the antiquarians’ pictorial evidence it was important to undertake field visits in order to ascertain their accuracy and the amount of damage sites have incurred since. The earliest antiquarians were those who visited Devon during the 16th century in order to collect material for the histories of England they were writing. These were followed by Devonian antiquarians, who from the 16th century onwards wrote histories of Devon, and a later group who visited, and in some cases excavated, archaeological sites. Antiquarians are discussed in depth where they have left us documentary evidence, and in some cases illustrations, from their research. The thesis explores six areas of research pursued by these antiquarians: barrows, hillforts, Roman sites, castles, religious houses and churches. Within the discussion of these types of sites, particular case studies are used to show the progression of archaeological techniques within antiquarian research, it was found that the majority of the sites described by antiquarians have not undergone any further archaeological investigation.