The Imperial Castle of Nuremberg (Kaiserburg Nürnberg
), probably the city's most iconic site. Seriously damaged by air raids in 194445, it was reconstructed and restored over the course of the next thirty years. The postcard is from a booklet that I bought when I was there with the AATG/PAD Preisträgerprogramm in 1984.
And here's the castle on a couple of older postal cards.
Bavaria, 1906 (Michel #PP5)
Germany, 1938 (Michel #P272)