This is the first book in a three-volume series on architectural history, richly illustrated and written for the general reader. Unpacking the history of Dublin’s architecture during the 20th century, each book covers a period, in chronological sequence. Volume I contains introductory historical essays of building culture in Dublin from 1900 to 1939; followed by 28 case studies ranging from iconic situations such as the 1917 rebuilding of Sackville Street lower (later O'Connell Street), to lesser-known structures like the concrete Oblates grotto, Inchicore (1929) or the public library, Drumcondra (1937). Each study is framed according to key historic questions, and raises issues around architectural technology and materials, patronage and urban planning, residents and ceremonial or daily use, and so on. Volume I presents an overview, in guidebook style, of c.90 sites; a survey of the city’s buildings over the period 1900 to 1939, not as a ‘best of’ but as a representation of architectural endeavour at the time.