Our Lady of Lourdes, kept on 11 February, commemorates the series of apparitions reported in 1858 by the fourteen-year-old Bernadette Soubirous in a grotto at Lourdes in the French Pyrenees, in which a lady later understood as the Virgin identified herself with the words "I am the Immaculate Conception", echoing the dogma defined four years earlier. A spring at the grotto became the focus of a healing cult, and Lourdes grew into one of the largest pilgrimage sites in the world, receiving millions each year, many of them sick.
What is distinctive about Lourdes is the institution built to test its own claims. The Lourdes Medical Bureau, and later an international medical committee, examine reported cures under medical scrutiny, and the church recognises only a small number, after long review, as inexplicable by current medicine; the great majority of reported cures are not so declared. This deliberate apparatus of scepticism, unusual in the history of shrines, means the site presents itself as submitting its wonders to examination rather than asserting them, and it has shaped how modern Catholicism handles claims of the miraculous.