This is the first guidebook devoted solely to twentieth-century buildings in metropolitan Pittsburgh. The introductory chapters explore the appearance and diverse meanings of "modern architecture" in the United States, and document the arrival of modern design in Pittsburgh from the turn of the twentieth century through the post World War II period, culminating in the completion of Point State Park. After an introduction to the language of architecture, the Guide presents a selection of 53 extant buildings and structures that embody aspects of twentieth-century architectural practice from 1903 to 1999. Some thirty additional structures are presented in three thematic sidebars. Many of the buildings and structures in the book have either been designated as local, state, and/or national landmarks or qualify for future designation. Some are endangered; others have been adapted to new uses. All are worthy of preservation. Extensive notes, a bibliography, and an index are provided. The book includes a Foreword by Lu Donnelly, editor of The Buildings of Pennsylvania: Pittsburgh and Western Pennsylvania (2010), and an Epilogue on selected twenty-first century buildings by Charles Rosenblum, PhD.