North Rhine-Westphalia in the context of "Rhine-Ruhr metropolitan region"

The Ruhr (/ˈrʊər/ ROOR; German: Ruhrgebiet [ˈʁuːɐ̯ɡəˌbiːt] , also Ruhrpott German pronunciation: [ˈʁuːɐ̯pɔt] ), also referred to as the Ruhr Area, sometimes Ruhr District, Ruhr Region, or Ruhr Valley, is a polycentric urban area in North Rhine-Westphalia, Germany. With a population density of 1,160/km and a population of over 5 million (2017), it is the largest urban area in Germany and the third of the European Union. It consists of several large cities bordered by the rivers Ruhr to the south, Rhine to the west, and Lippe to the north. In the southwest it borders the Bergisches Land. It is considered part of the larger Rhine-Ruhr metropolitan region of more than 10 million people, which is the third largest in Western Europe, behind only London and Paris.

The Ruhr cities are, from west to east: Duisburg, Oberhausen, Bottrop, Mülheim an der Ruhr, Essen, Gelsenkirchen, Bochum, Herne, Witten, Hagen, Dortmund, Hamm and the districts of Wesel, Recklinghausen, Unna and Ennepe-Ruhr-Kreis. The most populous cities are Dortmund (with a population of approximately 612,065), Essen (about 583,000) and Duisburg (about 497,000).

The Rhine-Ruhr metropolitan region (German: Metropolregion Rhein-Ruhr) is the largest metropolitan region in Germany, with over ten million inhabitants. A polycentric conurbation with several major urban concentrations, the region covers an area of 7,110 square kilometres (2,750 sq mi), entirely within the federal state of North Rhine-Westphalia. The Rhine-Ruhr metropolitan region spreads from the Ruhr area (Dortmund-Bochum-Essen-Duisburg) in the north to the urban areas of the cities of Mönchengladbach, Düsseldorf (the state capital), Wuppertal, Leverkusen, Cologne (the region's largest and Germany's fourth largest city), and Bonn in the south. The location of the Rhine-Ruhr at the heart of the European Blue Banana makes it well connected to other major European cities and metropolitan areas such as the Randstad, the Flemish Diamond and the Frankfurt Rhine Main Region.

The metropolitan area is named after the Rhine and Ruhr rivers, which are the region's defining geographical features and historically its economic backbone.

The Rhine (/raɪn/ RYNE) is one of the major rivers of Europe. The river begins in the Swiss canton of Graubünden in the southeastern Swiss Alps. It forms part of the Swiss-Liechtenstein border, then part of the Swiss-Austrian border. From Lake Constance downstream, it forms part of the Swiss-German border. After that the Rhine defines much of the Franco-German border. It then flows in a mostly northerly direction through the German Rhineland. Finally, the Rhine turns to flow predominantly west to enter the Netherlands, eventually emptying into the North Sea. It drains an area of 185,000 km.

Its name derives from the Gaulish Rēnos. There are two German states named after the river, North Rhine-Westphalia and Rhineland-Palatinate, in addition to several districts (e.g. Rhein-Sieg). The departments of Bas-Rhin and Haut-Rhin in Alsace (France) are also named after the river. Some adjacent towns are named after it, such as Rheinau, Stein am Rhein, Rheineck, Rheinfelden (Switzerland) and Rheinfelden (Germany).

A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long, large streams are usually called rivers, while smaller, less voluminous and more intermittent streams are known, amongst others, as brook, creek, rivulet, rill, run, tributary, feeder, freshet, narrow river, and streamlet.

The flow of a stream is controlled by three inputs – surface runoff (from precipitation or meltwater), daylighted subterranean water, and surfaced groundwater (spring water). The surface and subterranean water are highly variable between periods of rainfall. Groundwater, on the other hand, has a relatively constant input and is controlled more by long-term patterns of precipitation. The stream encompasses surface, subsurface and groundwater fluxes that respond to geological, geomorphological, hydrological and biotic controls.

Rhineland-Palatinate (/ˌraɪnlænd pəˈlætɪnɪt, -lənd-/ RYNE-land pə-LAT-in-it, -⁠lənd-, US also /-ɪneɪt/ -⁠in-ayt; German: Rheinland-Pfalz [ˌʁaɪnlant ˈpfalts] ; Luxembourgish: Rheinland-Pfalz [ˌʀɑɪ̯nlɑm ˈpfɑlts]; Palatine German: Rhoilond-Palz) is a western state of Germany. It covers 19,846 km (7,663 sq mi) 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 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.

The Ruhr (German pronunciation: [ʁuːɐ̯] ) is a river in western Germany (North Rhine-Westphalia), a right tributary (east-side) of the Rhine.

The Lippe (German pronunciation: [ˈlɪpə] ) is a river in North Rhine-Westphalia, Germany. It is a right tributary of the Rhine and 220.3 km (136.9 mi) in length with an elevation difference of 125 metres and a catchment area of 4.890 km².The source is located at the edge of the Teutoburg Forest in Bad Lippspringe close to the city of Paderborn. It runs westward through Paderborn, Lippstadt and then along the northern edge of the Ruhr area, parallel to the river Emscher and river Ruhr. The river finally enters the Rhine at Wesel.

The Bergisches Land (German pronunciation: [ˈbɛʁɡɪʃəs ˈlant], lit. 'Bergian Land') is a low mountain range in the state of North Rhine-Westphalia, Germany, east of the Rhine and south of the Ruhr. The landscape is shaped by forests, meadows, rivers and creeks and contains over twenty artificial lakes. Wuppertal is the biggest town, while the southern part has economic and socio-cultural ties to Cologne. Wuppertal and the neighbouring cities of Remscheid and Solingen form the Bergisches Städtedreieck (Berg City Triangle).