A campaign poster in Dublin encourages voters to say no to same-sex marriage ahead of a referendum in Dublin on Friday. Paul Faith/AFP/Getty Images hide caption

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A sinkhole that opened on Dame Street in Dublin, Ireland, this week is suspected of being caused by an old tunnel lawmakers used to visit brothels. The street is seen here in 1911. Topical Press Agency/Getty Images hide caption

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A an employee works at Amazon's fulfillment center in Rugeley, central England, in 2012. President Obama wants Amazon and other U.S. companies to bring more of their overseas earnings home. Phil Noble/Reuters/Landov hide caption

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The Apple campus in Cork, southern Ireland, employs 4,000 people — though its financial benefits are felt across the city. But Ireland's attractive tax laws — which have lured other industry leaders — are now under scrutiny. Paul Faith/AFP/Getty Images hide caption

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Not-so-authentic Irish: a Celtic knot tattoo. Tattoo parlors in Ireland say almost all the customers requesting this are American. Christa Burns/Flickr hide caption

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Leinster House is home to the upper house of the Irish parliament. Some members are calling for an investigation into children's deaths and burials at church-run homes. Peter Muhly/AFP/Getty Images hide caption

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Tech companies around the world have set up shop in the financial district in Dublin, Ireland. Peter Muhly/AFP/Getty Images hide caption

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Plant pathologists sequenced the genome of 19th century potato specimens like this one from London's Kew Gardens herbarium, collected during the height of the Irish famine in 1847. Marco Thines/Senckenberg Gesellschaft für Naturforschung hide caption

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Tea a dangerous habit? Women have long made a ritual of it, but in 19th century Ireland, moral reformers tried to talk them out of it. At the time, tea was considered a luxury, and taking the time to drink it was an affront to the morals of frugality and restraint. iStockphoto.com hide caption

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