Central Europe is a region forming the heart of Europe. It includes the German-speaking countries, four former Warsaw Pact member states that have successfully joined the European Union, and Slovenia, a former Yugoslav republic, now also a member of the EU. Only Switzerland and tiny Liechtenstein are not EU member states but share close economic and cultural ties with the region but also have stayed away largely for economic and historical reasons. It is a large and important region stretching from the Baltic and North Sea in the north to the Adriatic in the south. It is also home to some of Europe's and the world's most prosperous economies and cities. Lastly, it includes the fabled mountain range of the Alps which acts a transition zone between the Latin, Germanic and Slavic cultures which all call the region home.