The first eleven pictures are inside the Treasury at the Hofburg Palace, featuring crowns, crosses, tapestries, garments and other artifacts, including the massive emerald in picture six,
which the Medici family in Florence coveted and offered 3 tons of of Gold!, but the Emperor refused to part with the emerald.
Pictures eleven through sixteen are in the gardens around the Upper and Lower Belvedere Palaces. Pictures seventeen and eighteen are of the Vienna City hall, the appropriately named Rathaus.
Picture nineteen is inside the Albertina Museum.