The Interior of the Palm House on the Pfaueninsel Near Potsdam by Carl Blechen https://www.rawpixel.com/image/8961515/the-interior-the-palm-house-the-pfaueninsel-near-potsdam-carl-blechenFree Image from public domain licenseAlexander I of Russia taking leave of Friedrich Wilhelm III and his wife, Luise von Mecklenburg-Strelitz, next to the tomb… https://www.rawpixel.com/image/13998791/image-cartoon-person-artFree Image from public domain licenseHome of the Prince Royal, Potsdam, Germany. by Benjamin West Kilburn https://www.rawpixel.com/image/14296137/home-the-prince-royal-potsdam-germany-benjamin-west-kilburnFree Image from public domain license