Info from Wikipedia
McHugh's Bar is a pub on Queen's Square in Belfast City Centre, Northern Ireland. It is one of the city's best known pubs and the oldest building in Belfast.

McHugh's was originally built as a private dwelling on the old Town Dock around 1711, probably later, though the real date is not officially established. Some time after this the dock was demolished and the River Farset was covered, although it still runs under Queen's Square and the adjacent High Street. Between 1715 and 1725 it was converted to a small pub.