sentences:  It takes its name from a "dún" (fort), which once stood on the hill that dominates the town and on which Down Cathedral was later built.Ptolemy, about the year AD 130, includes it (in Latin) as "Dunum" in his list of towns of Ireland.The Gaelic name of the town was "Ráth Celtchair" (anglicised 'Rathkeltair') named after the mythological warrior of Ulster called Celtchar (in modern Irish