The most intersting vault light that I found in Vienna was the one made by the German copmany Luxfer, examples of which can also be found in Lviv (posts are here and here ).
As I suspected, few doors were open or unlocked to Vienna's residential buildings. Unlike Lviv, the vast majority of doors are in good condition and kept locked, usually with a key and not code. Therefore, I didn't have the opportunity to see many entranceways. However, I lucked out and did find a few beautiful corridors and stairwells. But I only found one tile with a manufacturer's mark.
In Vienna, at almost every step there is an old manhole cover or storm drain. Fortunately, most include a date along with the manufacturer's mark, and this is true even for modern ones. Valve cover from 1898 Below square storm drains ranging from 1896 to 1957, posted in chronological order.
Vienna has a lot of guard stones , as do probably all old European cities and towns. Most that I found were made of stone, but I also found some metal ones. In the medieval center stone is more common, while metal barriers are common for newer buildings. Looks as though these were cut in half. Metal The shape of these is similar to ones I've seen in Lviv Interestingly, these are to protect a tree.