#header-photos-links {
        background-image: url('stadtarchiv_FILES/stadtarchiv-links.jpg');
      }
      
      #header-photos-mitte {
        background-image: url('stadtarchiv_FILES/stadtarchiv-mitte.jpg');
      }
      
      #header-photos-rechts {
        background-image: url('stadtarchiv_FILES/stadtarchiv-rechts.jpg');
      }