Ardee (Baile Átha Fhirdhia in Irish), originally called Atherdee, its name is derived Áth Fhirdia (the Ford of the Ferdia), from the mythological four day battle between Cúchulainn and Ferdia, for the defence of Ulster from Queen Maeve of Connacht. It is sited on the river Dee. The river was a central part of the town's milling industry in the past. Ardee boasts two 13th century castles on its main street, Ardee or St. Leger's Castle and Hatch's Castle.