Today is a rather unique feast day in honour of our Lady - Our Lady of the Snows. It is an odd title, and it is even odder to be celebrating such a feast day during the high summer days of August. There is a very good reason for it, though, for it commemorates a miraculous fall of snow, which marked the location upon which Santa Maria Maggiore, one of the principle churches in Rome, was to be built. The legend of our Lady of the Snows runs like this: In the 4th century, during the reign of Pope Liberius, a holy man named John and his wife, being childless, made a vow to leave their earthly possessions to our Lady, and prayed that she would inspire them how best to dispose of their wealth in her honour. In answer to their prayer, she appeared to the holy couple, in a dream, and to the Holy Father as well, requesting that they build a church in her name upon the Esquiline Hill, and that she would give them a sign to show where the exact location was to be. The following morning, they all went in procession to the Esquiline Hill, to discover that a heavy snow had fallen during the night, to mark the location of Our Lady's church.
The Basilica of Santa Maria Maggiore is one of the oldest churches in the world to be dedicated to our Lady. It contains two very special relics, relating to her motherhood: a very ancient painting of the Madonna and Child, which is attributed to St. Luke; and the Crib of our Lord. It is the possession of that Crib that gives the Basilica its secondary title of Santa Maria del Presepe - St. Mary of the Crib.
On the feast of Our Lady of the Snows each year, a shower of white rose petals are dropped from the roof during Mass, to commemorate the miraculous snow that marked the church's foundation. Here is a clip of it: