with the German states of Lower Saxony to the north and northeast, Rhineland-Palatinate to the south and Hesse to the southeast. Approximately half of the state is located in the relative low-lying terrain of the Westphalian Lowland and the Rhineland, both extending broadly into the North German Plain. A few isolated hill ranges are located within these lowlands, among them the Hohe Mark, the Beckum Hills, the Baumberge and the Stemmer Berge. The terrain rises towards the south and in the east of the state into parts of Germany's Central Uplands. These hill ranges are the Weser Uplands – including the Egge Hills, the Wiehen Hills, the Wesergebirge and the Teutoburg Forest in the east, the Sauerland, the Bergisches Land, the Siegerland and the Siebengebirge in the south, as well as the left-Rhenish Eifel in the southwest of the state. The Rothaargebirge in the border region with Hesse rises to height of about 800 m above sea level. The highest of these mountains are the Langenberg, at 843.2 m above sea level, the Kahler Asten (840.7 m) and the Clemensberg (839.2 m). The planimetrically determined centre of North Rhine-Westphalia is located in the south of Dortmund-Aplerbeck in the Aplerbecker Mark (51° 28' N, 7° 33' Ö). Its westernmost point is situated near Selfkant close to the Dutch border, the easternmost near Höxter on the Weser. The southernmost point lies near Hellenthal in the Eifel region. The northernmost point is the NRW-Nordpunkt near Rahden in the northeast of the state. The Nordpunkt has located the only 100 km to the south of the North Sea coast. The deepest natural dip is arranged in the district Zyfflich in the city of Kranenburg with 9.2 m above sea level in the northwest of the state. Though, the deepest point overground results from mining. The open-pit Hambach reaches at Niederzier a deep of 293 m below sea level. At the same time, this is the deepest man-made dip in Germany. The most important rivers flowing at least partially through North Rhine-Westphalia include: the Rhine, the Ruhr, the Ems, the Lippe, and the Weser. The Rhine is by far the most important river in North Rhine-Westphalia: it enters the state as Middle Rhine near Bad Honnef, where still being part of the Mittelrhein wine region. It changes into the Lower Rhine near Bad Godesberg and leaves North Rhine-Westphalia near Emmerich at a width of 730