The Sanctuary of Our Lady of Fátima (Santuário de Fátima) is one of the world’s largest Catholic pilgrimage sites, attracting between 4 and 5 million visitors every year. Here, between 13th May and 13th October 1917, three shepherd children are believed to have witnessed six apparitions of the Virgin Mary, who imparted various messages and predictions about the future. During the last of these apparitions it is said that around 50,000 observers witnessed the sun moving around in the sky in a way which defied the laws of cosmology.