East Germany. Not too many Slavs left in the former stomping grounds of the Wends. The (Ostro)Goths had been in parts of eastern Europe before, but didn’t really hang around long. Northeastern Europe was settled more by Balto-Slavic peoples. Then a series of raids, crusades, and settlements (Ostsiedlung) gradually stripped the land away in favor of Germanics.
There’s always been a minority of Slavic folks and their language in eastern Germany, but the cultural and AFAIK genetic Germanicization of that area is a fait accompli. The Balts managed to get back their territory from what used to be eastern Prussia, and the Slavs managed to take back Silesia in central Europe, but that’s it. Berlin and Leipzig aren’t going back any time soon.
Berlin — Slavic berl- (“swamp”) + -in
Leipzig — Slavic Lipsk (“linden tree settlement”)
Dresden — Slavic Drežďany (“people of the forest”)
Potsdam — Slavic Poztupimi (“beneath the oaks”?)
Chemnitz — Slavic Kamjenica (“stony brook”)
Lübeck — Slavic Liubice (“lovely”)
Rostock — Slavic Roztoc (“broadening of the river”)
Cottbus — Slavic Chotebud (Sorbian personal name)
Also, German surnames ending in “-itz” bear the Slavic suffix seen in “-ic” / “-ich” / etc. — von Clausewitz, Nimitz, and so on.
Although the eastern Germans don’t seem to be very linguistically or genetically Slavic, they do have that whole dark, brooding Sturm und Drang mindset that is more (Balto-)Slavic than Germanic. Admittedly, Nords are somewhat that way, but more in a resigned suicidal way — not in a resentful, revenge fantasy way like the narrator of Notes from Underground.
Those East German place names sound about as Germanic as Massachusetts and Minnesota sound English. Yet unless we read into the history, we don’t stop and think, Gee, those city names sure don’t sound like Krauttenhammer, Neumannerfetting, Gedorfenbacher, Schlausbund, or whatever our naive ears would have expected. Sometimes it’s hard to see what’s right under our noses.