Unlike the vast majority of Rhine castles, "the Pfalz" was never conquered or destroyed, withstanding not only wars, but also the natural onslaughts of ice and floods by the river. Its Spartan quarters held about twenty men and was used to collect toll in medieval time.
This very old card is by Karl Fischer, Eltville and can be found in CATAWIKI-online Auction for special objects.
Thank you Christoph for this very old and bristle Postcrd which surprisingly reached unharmed except for a small cut in the ear.
2015 stamp on Wild Germany - Ostsee-Boddenlandschaft