Viking raids in the Rhineland
The area known today as the Rhineland begins at the confluence of the Moselle and the Rhine and ends at Emmerich, where the Rhine divides into the Lek and the Waal to form a delta. In the east, the Rhineland ends close to the Rhine itself, being bounded by low mountain ranges such as the Siebengebirge or Bergisches Land. To the west its boundary is less well defined, but in general parlance it runs beyond the present state border with the Netherlands, i.e. east of the Meuse. Because the modern state of Rhineland-Palatinate lies south of the Moselle, the low mountain range of the Eifel north of the river is usually seen as belonging to the Rhineland. Areas south of the Moselle, such as the Hunsrück, are also considered to be part of the Rhineland.
Cologne Lowland
The Cologne Lowland, also called the Cologne Bay or, less commonly, the Cologne Bight (), is a densely populated area of Germany lying between the cities of Bonn, Aachen, and Düsseldorf/Neuss. It is situated in the southwest of the state of North Rhine-Westphalia and forms the natural southern conclusion of the Lower Rhenish lowlands and the transition to the Rhenish Massif ("Rheinische Schiefergebirge" or "Rhenish Slate Mountains"). The Cologne Bight is surrounded by the High Fens and the Eifel to the west of the Rhine and by the uplands of Bergisches Land to the east of the Rhine. In the south and southeast the rising Rhine Massif, visible from far off by the silhouette of the Siebengebirge, surround the head of the bight at Königswinter. To the northwest the Cologne Bight opens out into the valleys of the Rhine and the Meuse, in the northeast it is bounded by the Münsterländer Kreidebecken (Münster Chalk Basin) of the Westphalian Bight.