The monograph deals with one of the masterpieces of architect Jože Plečnik (1857–1972), National and University Library in Ljubljana, built between 1936 and 1941. The author, main researcher of Plečnik’s oeuvre, discusses the history of its construction, various projects, reconstruction after the plane crash in 1944, furthermore he analyses the architecture of the building. Beside the study, the book is also important due to its illustrations, not only contemporary photographs, but also complete Plečnik’s projects and sketches, made during the processes of the planning and construction, which are published for the first time.