Final answer:
Mary appeared eighteen times in the grotto at Lourdes, France to Bernadette Soubirous in 1858, leading to its significance as a pilgrimage site.
Step-by-step explanation:
Mary is believed to have appeared eighteen times in the grotto at Lourdes, France. These apparitions occurred in 1858, when a 14-year-old girl named Bernadette Soubirous claimed to see a lady who later identified herself as the Immaculate Conception.
These events led to Lourdes becoming one of the world's most important sites of pilgrimage and religious tourism, with many visitors coming to seek healing and spiritual comfort.
The question is referring to the appearances of Mary at the grotto in Lourdes, France. According to the provided information, there are no specific details about how many times Mary appeared at the grotto. Therefore, it is difficult to provide an exact number.
The information given mentions different references to Mary in various contexts, such as relics, icons, and sacred sites, but none of them directly state the number of appearances.