St Patrick's Day

A group of friends from Austria get in to the spirit of the festivities. Photograph: Alan Betson/The Irish Times

Revellers celebrate at an Irish pub during the Singapore St Patrick's Day Street Festival. Photograph: Chris McGrath/Getty Images

Dennis O'Mann and his doll watch the St. Patrick's Day Parade in New York. Photograph: Carlo Allegri/Reuters

The Sydney Opera House goes green as part of a global initiative by Tourism Ireland which also sees the Pyramids of Giza, the Christ the Redeemer statue in Rio de Janeiro, the London Eye, Selfridges in London, Niagara Falls, the Prince's Palace of Monaco, Burj al Arab in Dubai and the Leaning Tower of Pisa, turn a shade of green this weekend. Photograph: Jean-Pierre Bratanoff-Firgoff

Tourists in Dublin for the St Patrick's festival look at a map outside the Tourist office on Suffolk Street. Photograph: Brenda Fitzsimons/The Irish Times

Renowned Dublin historian Pat Liddy photographed on South William Street guiding a tour of Dublin in celebration of St Patrick. Photograph: Brenda Fitzsimons /The Irish Times

Kimberly Anderson wears an "Irish Princess" necklace as she watches the St Patrick's Day Parade in New York. Photograph: Carlo Allegri/Reuters

Romania's Parliament Palace in Bucharest illuminated in green light ahead of St Patrick's Day. Photograph: Bogdan Cristel/Reuters

James Hennessy, aka 'St Patrick', with a nine-foot adult American Alligator at the Reptile Village, Gowran, Co Kilkenny, as preparations for St Patrick's Day continue in Dublin and around the world. Photograph: Julien Behal/PA Wire

Members of FDNY march on New York's Fifth Avenue during the 252nd annual St Patrick's Day Parade. Photograph: Ramin Talaie/Getty Images

Workers dye the Chicago River green to kick off the city's St Patrick's Day celebration in Illinois. The dyeing of the river has been a tradition in the city for 43 years. Photograph: Scott Olson/Getty Images

Aras an Uachtarain illuminated green for the first time this year for St Patrick's Festival. Photograph: Peter Moloney/OPW Ireland

The EDF London Eye is lit green by Tourism Ireland to celebrate St Patrick's Day in London. Photograph: David Parry/PA Wire

Visitors from Australia join the peoples parade ahead of the St Patricks Day Parade during festivities on Dublins O'Connell Street. Photograph: Alan Betson/The Irish Times

Babon Njiel from Gambia; Kamil and Meg Borawscy from Poland; and Howard Davis and Mark Harrison from Yorkshire get in to the spirit of St Patricks Day on O'Connell Street, Dublin. Photograph: Alan Betson/The Irish Times

St Patricks Day festivities at the start of the Festival Parade on O'Connell Street. Photograph: Alan Betson/The Irish Times

Matthew Debono, Karl Briffa, Ritianne Attard and Heather Scicluna from Malta in Dublin today. Photograph: Alan Betson/The Irish Times

The Mayobridge Band from Co Down performing in the People's Parade, Dublin.Photograph: Brenda Fitzsimons / The Irish Times

The Duchess of Cambridge visits the 1st Battalion Irish Guards to attend the St. Patrick's Day Parade at Mons Barracks, Aldershot. Photograph: Toby Melville/PA Wire

A reveller during the St Patrick's Day parade through Dublin city centre. Photograph: Julien Behal/PA Wire

People in fancy dress taking part in a charity event to celebrate St Patrick's Day and raise money for local charities in the town of Portstewart, Co Derry. Photograph: Cathal McNaughton/Reuters

Taoiseach Enda Kenny with Rev Nicholas DiMarzio (left), Bishop of Brooklyn, and Monsignor Michael J. Curran (right), pastor of St. Thomas More Church, hi-fives an altar girl as he arrives for St Patrick's Day Mass. Photograph: Michael Nagle/Getty Images

Eimear Curran and Rebecca Daly of Mahon take a break in the shade during the parade. Photograph: Clare Keogh

A member of Ascension Baton Twirlers keeps warm before taking part in the parade as part of the St Patrick's Festival in Cork City. Photograph: Clare Keogh