Parliament is the space where politics literally takes shape. Here, collective decisions take form in a specific setting where relationships between political actors are organized through architecture. The architecture of spaces of political congregation is not only an expression of a political culture, it also shapes this culture. Since 2010, architecture office XML has researched the architecture of spaces of political congregation. This book explores the double-sided relationship between space and politics by documenting and comparing the plenary halls of the parliaments of all 193 United Nations member states. Almost like a manual archive, the book documents the rooms in the same style and scale and also provides key data and the assembly hall's location within the larger parliament building. Organized as a lexicon, the book allows comparison of all 193 national parliaments in the world.