Marian apparitions – occurrences where people say they have witnessed the Virgin Mary – are recorded throughout history. One such famous mystery happened in Portugal on this day in 1917. Three shepherd children claimed to have been visited by Mary with an important message for human kind. After a series of visitations, on October 13, 1917 a crowd of anywhere between 30,000 to 100,000 people witnessed what became known as the Miracle of the Sun – at the moment the shepherd children said it would, the sun twirled in the sky, became a mix of colors and descended to Earth. The event has never been explained scientifically, and of the three secrets that Mary allegedly gave to the shepherd children, two were made immediately public and one had been locked away by the Vatican until 2000.