Madonella or Santuari Muralli are found almost everywhere in Italy, attached to buildings and on street corners. Most are centuries old, maintained by the people of the neighbourhood or of a parish church. Many created by great artists as a commission by a religious congregation.
People pass by them, some will stop to say a short prayer, others just nod to them as if a neighbour. On some streets people leave plants or flowers, votive candles.
There is an unwritten rule and everyone knows that the flowers and votive candles are never to be disturbed. This is a sacred place even if just on a busy street. It is as if there is an invisible precinct. The idea of these Madonella (little Madonnas) or Wall Shrine is as old as Rome, in antiquity on street corners you would have the local divinity protecting the neighbourhood usually near the local tavern which served also as a Club for the area, serving food and drink. The divinities were there to protect and they were different in each neighbourhood, they also had a local story attached to them and were said to perform miracles against an attack by unfriendly foreigners. Rome is a superstitious place and Romans have always been known to be a superstitious people.
With the gradual transformation of the City in the fourth century A.D. with the imposition by Emperor Constantine of the Christian religion, slowly these old pagan shrines are changed to Christian ones. The most popular new figure is the Virgin Mary, often associated with Venus or Aphrodite. Since Venus usually appears with a cupid, the Virgin Mary appears with a new born baby Jesus, voilà transformation and a gullible public is none the wiser.
When we lived on Via Asmara there was such a Madonella, at the bottom of the street was a big high school and many students walked back and forth passing in front of it. There was always flowers and many votive candles and I remember thinking that the kids might be tempted to steal or break what was left in a moment of piety. No never they simply walked pass it without ever touching anything. They obviously knew better than to desecrate such a site.
A lovely tradition to see such sanctuaries attached to the walls of apartment buildings or commercial ones. Just a tradition, it what was once a very Catholic country, like all places Italy has changed a lot but this millennia old tradition persists.