At a first glance, the Western Rhenish Slate Mountains (WRSM) appear to be a rather unique uplifted block of the Paleozoic Variscan orogeny dominated by Paleogene or older planation surfaces. However, a closer look reveals remarkable differences between the regionally significant sceneries, some of which date back well before the Cenozoic. Remnants of fluvial, lacustrine, and brackish to marine Paleogene sediments are widespread in the WRSM and the subtropical climatic conditions are responsible for the development of the extensive planation surfaces and the Mesozoic-Tertiary weathering mantle (MTV). During the Quaternary uplift and Pleistocene climate cyclicity created valley incision and terraces staircases. Quaternary deposits consist of fluvial sediments. In the WRSM Quaternary sediments encompass cover beds on slopes, loess or loess derivates, and Holocene peat bogs. Cenozoic volcanism is abundant in the Eifel, and the volcanic landforms produced in the two Eifel volcanic fields during the Quaternary are generally much better preserved. A number of maars dating from the last glacial cycle still contain lakes and have given rise to the worldwide use of the term maar. The maar lakes and the silted-up dry maars with varved sediments are excellent archives of paleoclimate and paleoecology.