On my first day in Rome, I enjoyed a morning walk on via Trastevere. I passed a wall of little plaques with “PGR” written on them. Some spelled out the phrase “Per Grazie Ricevute.” There was also an altar to the Virgin Mary.
Since I only know that grazie means “thanks,” I could only assume it was a gratitude wall.
When I returned home, I did more research on the wall and its tradition of appreciation.
The wall of Per Grazie Ricevute is a thanksgiving wall for those who've had prayers answered. They manifest their gratitude by attaching small PGR plaques on the wall. It represents thanks for any miracle, and the names on the plaques are the persons whom the miracle touched.