Did any historic German cities survive WWII intact? If so, which?
One German city that fits your question is the old university town of Heidelberg. There is a story (myth?) that an unwritten gentlemen’s pact existed in WW2: Luftwaffe don’t bomb Oxford and Cambridge; Allies don’t bomb Heidelberg. I don’t believe it: the Cowley suburb of Oxford was heavily bombed (Morris factories). But, whatever the reason, the Allies never did pound Heidelberg with either bombs or (later) artillery. The only damage to Heidelberg was when retreating German troops blew up the Karlsbridge over the Neckar River. Apart from Heidelberg, only two other historic German cities, Celle and Flensburg, survived intact from WW2. Two others, Lubeck and Bamberg were only lightly damaged. ———————— SUBSEQUENT EDIT: It is easy to assume that some of Germany’s cities escaped bombing when you visit and see those medieval-looking buildings. Most of them are post-war reconstructions (e.g. Koln, Dusseldorf, Sachsenhausen). Regensburg was heavily bombed (see Schweinfurt-Regen
