Westphalian Lowland

From a natural region perspective the Westphalian Lowland major unit group is sub-divided into the following three-figure major units:[3][4] The Westphalian Lowland has the character of a basin because it is bounded by ridges of the Lower Saxon Hills from the northeast to east and by the northern part of the Süder Uplands to the south.

From east of Mülheim its unremarkable boundary with the Lower Rhine Plain runs northwards via Bottrop, Dorsten, Borken and finally along the state border with the Netherlands, to Gronau.

The use of the term Bucht ("bay" or "bight") stems from the geological origin of the region which is half surrounded by the ridges of the Central Uplands.

The majority of the population of the Westphalian Lowland live in the area bordering the southern perimeter, in the region of the historic Hellweg east–west trade route through Germany, and especially in the northern Ruhr.

At various sites in the Westphalian Lowland giant ammonites have been found in Cretaceous layers of rock below the surface, for example when the underground railway network was being built in Dortmund.