Social housing has a long tradition in Europe. Since the early 20th century, these often anonymously built and unappreciated structures have arisen all across the suburbs of Europe’s major cities. In the multidisciplinary and international research project Mapping Public Housing, the Center for Studies in Architecture and Urbanism at the University of Porto’s Faculty of Architecture has been tracing the architectural heritage of social housing. The findings demonstrate that, in many cases, vibrant neighbourhoods and entire city districts have emerged from such social housing programs. This book takes a closer look at exemplary developments in Germany, Great Britain, Portugal, Switzerland, and Spain. The case studies cover a wide range of social and historical contexts, from the beginnings of social housing in Portugal sparked by German investment during World War I to the propaganda policies associated with subsidised housing for the working class in the 1940s, and to sustainable concepts and ideas for the future. Hidden in Plain Sight offers a wide-ranging panorama that recognises the development of subsidised residential construction as a part of Europe's cultural history and traces the important role that state-funded housing has played in the emergence of the European welfare state.