Today was a simple bus tour. You pay one fee and hop on and off the bus at will as the next bus comes along every ten minutes.
Saw the Guinness Factory, the Prime Minister’s mansion, Phoenix Park, the O'Connel Street Spire (http://en.wikipedia.org/wiki/Spire_of_Dublin), numerous churches and museums, and the Dublin Zoo. We took the train from Dun Laoghaire station to the Dublin Connolly station then walked about a mile to O’Connel Street right to the base of the spire. From there we picked up our tickets for the tour and caught the bus only a block away.
Now I sit in the lobby of the Royal Marine Hotel sipping hot chocolate and organizing my 1500+ photos taken so far.
Tomorrow I fly back to Boston for two days then home on Saturday.