What does Dún Laoghaire mean?

The name Dún Laoghaire (also spelled Dún Laoire) is derived from Irish and means "Laoghaire's Fort". In Irish mythology, Laoghaire was a sea god. The name Dún Laoghaire is sometimes translated as "Fortress of the Vikings" or "Viking Fortress", but this is a folk etymology and not accurate to its historic origins.