Saint Patrick´s Day is celebrated on 17th March.
Saint Patrick is the patron saint of Ireland because he brought Christianity to the island.
According to the legend, he used the shamrock , which was sacred for the Druids,
to explain about God and the Trinity.
The legend also tells that he drove the snakes out of Ireland.
The fact is that there are no snakes in Ireland.
Probably because it is separated from the rest of the continent.
 Some people think that the story of the snakes is a metaphore
because Saint Patrick converted pagans (whose symbol is usually a snake) to Christianism.
Saint Patrick´s Day is celebrated all around the world , not only in Ireland.
People with Irish ancestors celebrate by wearing green clothes and taking part in the festivities.
There is usually a parade and the one in New York is the biggest.
Even The Empire State Building turns green for the event!