Rhineland-Palatinate ( , ; ; ; ) is a western state of Germany. It covers and has about 4.05 million residents. It is the ninth largest and sixth most populous of the sixteen states. Mainz is the capital and largest city. Other cities are Ludwigshafen am Rhein, Koblenz, Trier, Kaiserslautern, Worms and Neuwied. It is bordered by North Rhine-Westphalia, Saarland, Baden-Württemberg and Hesse and by the countries France, Luxembourg and Belgium. Rhineland-Palatinate was established in 1946 after World War II, from parts of the former states of Prussia (part of its Rhineland and Nassau provinces), Hesse (Rhenish Hesse) and Bavaria (its former outlying Palatinate kreis or district), by the French military administration in Allied-occupied Germany. Rhineland-Palatinate became part of the Federal Republic of Germany in 1949 and shared the country's only border with the Saar Protectorate until the latter was returned to German control in 1957. Rhineland-Palatinate's natural and cultural heritage includes the extensive Palatinate winegrowing region, picturesque landscapes, and many castles and palaces. Rhineland-Palatinate is currently the only federal state in Germany where nuclear weapons are stored extraterritorially under the responsibility and supervision of US forces. History The state of Rhineland-Palatinate was founded shortly after the Second World War, on 30 August 1946. It was formed mainly from the southern part of the Prussian Rhine Province (the of Koblenz and Trier), from Rhenish Hesse, from the western part of Nassau and the Bavarian Rhenish Palatinate minus the county of Saarpfalz. The Joint German-Luxembourg Sovereign Region () is the only unincorporated area of the state of Rhineland-Palatinate. This condominium is formed by the rivers Moselle, Sauer, and Our, where they run along the border between Luxembourg and Rhineland-Palatinate or the Saarland. Emergence The present state of Rhineland-Palatinate formed part of the French Zone of Occupation (1945–1949) after the Second World War. It comprised the former Bavarian Palatinate, the ("government districts") of Koblenz and Trier (which formed the southern part of the Prussian Rhine Province), the parts of the Province of Rhenish Hesse () west of the River Rhine and belonged to the People's State of Hesse (), parts of the Prussian province of Hesse-Nassau (Montabaur), and the former Oldenburg region around Birkenfeld (Principality of Birkenfeld). On 10 July 1945, the occupation authority on the soil of the present-day Rhineland-Palatinate transferred from the Americans to the French. To begin with, the French divided the region provisionally into two "upper presidiums" (),