In several of Kraków’s pre-WWII buildings, one can find inscriptions near the entrance asking those entering to “wipe your shoes” (“Uprasza się obuwie wycierać”). Maintaining a clean building would have been more difficult in those times as fewer streets were paved, making it muddier than today. There would have also been a lot of horse manure around. Furthermore, many of the buildings once had carpeted stairs, so it was even more important to not bring in mud and dirt from the outside. This was also why little metal boot scrapers were added near the entrance of many buildings.
Interestingly, I have not found any such old inscriptions in Lviv.
The terrazzo floor example is especially interesting to me because rather than the usual greeting that is often found on such floors – the Latin greeting “Salve” (or Polish variant “Salwe,”), or even the year of the building’s construction – the mosaic instead welcomes guests with a reminder to “wipe your feet.”
Also, near one of the old inscriptions is a modern paper sign asking those entering to “disinfect” one’s shoes by wiping them on the provided modern boot scrubber.