This paper presents the result of my research in Sweden and my view on the relationships between physical geography (here mainly geomorphology) and geology. I developed a method for identification and mapping denudation surfaces formed in the Precambrian basement. South Sweden turned out to be a key area with cover rocks of different age directly on the basement. The relief differences in the basement are connected to the different sedimentary covers with a flat and inclined sub-Cambrian surface and a hilly and inclined sub-Cretaceous surface. The crosscutting horizontal South Smaland Plain was classified as a peneplain, as it is a surface graded to a distinct base level. Besides the basement forms and remnant cover rocks, saprolite remnants are important for the identification of denudation surfaces. The mapping method was ultimately labeled Stratigraphic Landscape Analysis (SLA) and used for conclusion on tectonics (uplift/subsidence and faulting). I obtained, as a physical geographer, a broad holistic knowledge on the relief differentiation of the basement rocks of Fennoscandia and on Swedish regional geology. This gave me the tool to identify denudation surfaces with the aid of the new digital elevation data and new geological knowledge of the surrounding continental shelf. The Swedish knowledge on the relationships between relief in the basement and its cover rocks is unique in the world. Maybe the relationship between denudation surfaces, cover rocks and tectonics ought to be a part of geology. Results of measurements, by different new techniques, are nowadays often analyzed based on hypotheses/theories. Observations of field conditions have become difficult to perform both within geology and geomorphology and seem to be considered as unscientific. Further, regional analysis, typical for geography, does not exist anymore.