A part of our Catholic tradition includes appearances (apparitions) of the Blessed Virgin Mother, most famous of the many are Our Lady of Lourdes, Our Lady of Fátima, and Our Lady of Guadalupe, to name a few. These appearances can be approved as “worthy of belief” by the local bishop or by the Vatican. The Church does not require belief in any apparition or other private revelation. However, she does exercise her maternal judgment for the protection of the faithful in declaring some apparitions to be inauthentic, others to be “worthy of belief.” Investigations into alleged apparitions are rigorous, and not done lightly.
I think most people can name Lourdes, Fatima, Guadalupe,and a handful of others. How many are there in total. I think you would be surprised. The list is long, but National Geographic has done us a favor and posted a world map of all reported Marian apparitions. So, I have re-posted the images here.
One that captured my interest was Mary, Mother of the World in Kibeho, Rwanda. I was not aware of the apparition. The apparitions, which began in 1981, communicated various messages to schoolchildren, including an apocalyptic vision of Rwanda descending into violence and hatred, possibly foretelling the 1994 Rwandan Genocide. The map shows it as having received Vatican recognition. After an episcopal approval by the local bishop, the Vatican may do nothing but it may release an official statement or after some time give non-written forms of approval such as a papal visit with the crowning of the associated icon or a gift such as a golden rose, the approval of the construction of (or elevation of an existing shrine to) a basilica, the establishment of a feast day, or the canonization of the associated visionary.The list of apparitions with Vatican recognition can be found here.