About 191 miles or 308 kilometres.
Killarney is approximately 4 hours by road or by train from Dublin
Dublin is the closest of the three places mentioned.
There is no train from Dublin to Waterville. You could get a train to Tralee or Killarney in county Kerry, the county that Waterville is in.
That would depend on traffic, but about 4 hours.
Castleisland is a town in mid Kerry where the main Limerick/Dublin road divides to Tralee and Killarney
Dublin Cork Donegal Dun Laoghaire Dundalk Galway Killarney Limerick Sligo Tipperary Waterford
The Guinness brewery, Trinity College Dublin, Blarney Castle, Glendalough, Cliffs of Moher, Dublin Zoo, the Lakes of Killarney, Connemara and many, many other things and places.
Dublin, Killarney, Blarney, Cork, Ring of Kerry, Dingle Peninsula, Bunratty, Ashford Castle Hotel (Cong)
Giant's Causeway, The Guinness brewery, Trinity College Dublin, Blarney Castle, Glendalough, Cliffs of Moher, the Titanic exhibition, Dublin Zoo, the Lakes of Killarney, Connemara and many, many others.
Samuel Derrick has written: 'Letters written from Leverpoole, Chester, Corke, the Lake of Killarney, Dublin, Tunbridge-Wells, and Bath'
Popular places in Ireland include Dublin, Newgrange, Connemara, the Giants Causeway, Blarney Castle, Killarney, the Burren, Glendalough and many, many others.
It will take about 4.5 hours You can see here: that Killarney is 192 miles and Kenmare is about another 25 minutes from Killarney. See the link below. For the quickest go over Molls Gap by the Black Valley