In 1858, in the grotto of Massabielle, near Lourdes in southern France, Our Lady appeared 18 times to Bernadette Soubirous, a young peasant girl who lived in complete poverty.
Bernadette always just referred to the beautiful vision as "aquero", meaning "that one" in her dialect. When asked who she was, Mary said that she was the Immaculate Conception, Bernadette didn't even know what the words meant and had to repeat them to herself so she wouldn't forget before she told the priest!
Mary also asked that a chapel be built on the site of the vision, and told the girl to bathe and drink from a spring in the grotto. The problem was - there was no spring there! Bernadette just dug at a muddy spot and rubbed mud on herself. People thought she had gone nuts. But after she left, a spring began to flow from the site. Today that spring flows at a rate of 32,000 gallons a day!
The water from this spring has shown remarkable healing power, though it contains no curative property that science can identify, and people come from all over the world to bathe in it and pray at the there. Lourdes has become the most famous modern shrine of Our Lady and is visited by over 6,000,000, not a typo - six million, people each year.