Germany is a federal parliamentary republic located in central Europe. It has 16 constituent states and a population of over 81 million people, making it the most populous country in the European Union. Some key landmarks in Germany include the Brandenburg Gate in Berlin, Alexanderplatz which is the largest public square in Berlin, and the Tiergarten which is Berlin's largest inner-city park. Several prominent museums are also located in Berlin, such as the Pergamon Museum, the Museum of Technology, and the Natural History Museum.