The fireplace at Sean's Bar is one of many features that remains from its past. Sean's Bar Established in 900 A.D., Sean’s Bar claims to be the oldest pub in Ireland.

The historic bar is located in the town of Athlone, roughly halfway between Dublin and Galway.

In 2000, it was accepted as a record for the oldest pub in Ireland by the "Guinness World Records," according to a letter the organisation sent to the pub.

Today, Sean's Bar has become popular with tourists from all over the world.

"The pub itself hasn't changed at all over the years," Declan Delaney, the manager of Sean's Bar, told Business Insider over email. "The building is a protected structure so any alteration to the main bar is forbidden."

Sean's has even been frequented by celebrities, including Mia Farrow, John C. Reilly, and Ray Meagher (Alf on the Australian TV soap "Home and Away"), who poured himself a pint on his visit in 2015.

For St. Patrick’s Day on March 17, Business Insider spoke to Delaney to find out more about the pub’s history.

Take a look inside below.