Thousand of revelers across Ireland and the United States are celebrating St. Patrick's Day with parades and pub crawls.
In Dublin, Ireland, crowds estimated to be in the hundreds of thousands braved chilly temperatures to take part in the annual festivities which kicked off with a tradition holiday parade.
While in New York City, Irish Prime Minister Enda Kenny joined Mayor Michael Bloomberg in leading the city's annual parade of bagpipers, stepdancers and Irish civic and cultural organizations.
Across the world dozens of landmarks including Egypt's pyramids and Brazil's Christ the Redeemer statue were flooded in green lights in honor of St. Patrick's Day.
The March 17 holiday commemorates the most recognizable of Ireland's patron saints and the arrival of Christianity in Ireland centuries ago.
More than 34 million Americans list their heritage as either primarily or partially Irish, a number seven times greater than the population of Ireland itself. A large number of their ancestors came to the U.S. in the 1840s to escape Ireland's great famine.