neighbouring states. Territorial sea: Physical geography The northern third of the country lies in the North European Plain, with flat terrain crossed by northward-flowing watercourses (Elbe, Ems, Weser, Oder). Wetlands and marshy conditions are found close to the Dutch border and along the Frisian coast. Sandy Mecklenburg in the northeast has many glacier-formed lakes dating to the last glacial period. Moving south, central Germany features rough and somewhat patternless hilly and mountainous countryside, some of it formed by ancient volcanic activity. The Rhine valley cuts through the western part of this region. The central uplands continue east and north as far as the Saale and merge with the Ore Mountains on the border with the Czech Republic. Upland regions include the Eifel, Hunsrück and Palatine Forest west of the Rhine, the Taunus hills north of Frankfurt, the Vogelsberg massif, the Rhön, and the Thüringer Wald. South of Berlin, the east-central part of the country is more like the low northern areas, with sandy soil and river wetlands such as the Spreewald region. Southern Germany's landforms are defined by various linear hill and mountain ranges like the two adjacent ranges of the Swabian and Franconian Alb (reaching approximately from the source of the Danube in the southwest of Baden-Württemberg, south of Stuttgart, across Swabia into Central Franconia and to the valley of the river Main) and the Bavarian Forest along the border between Bavaria and the Czech Republic. The Alps on the southern border are the highest mountains, but relatively little Alpine terrain lies within Germany (in southeastern Swabia and Upper Bavaria) compared to Switzerland and Austria. The Black Forest, on the southwestern border with France, separates the Rhine from the headwaters of the Danube on its eastern slopes. Climate The north–south difference in Germany, between 55°03"N (at List on Sylt) and 47°16"N (around Oberstdorf, Bavaria) equals almost eight degrees of latitude (or 889 km), which can be seen especially during the warm season in the differences between the average temperatures. Besides that, there is a strong west–east cline in temperature. This is explained by the North western Germany’s flat and open landscapes and its closeness to the sea, and South's higher terrain, larger distance from the sea, and the Alps. These mountains prevent much of the usually warmer Mediterranean air blowing into southern Germany. To the north of the Alps and the Carpathians, the local climate becomes colder, even at