Mentioned by Dublin 1 day itinerary
Dublin in 1 Day Itinerary
"The buses will take you past the major sights and, depending on which tour you choose (grab some leaflets the evening before or do some research on the internet), even far-flung attractions like the Guinness Brewery, Kilmainham Gaol, and Phoenix Park will be seen. The main thing to remember here: get a good seat on top, enjoy the view, listen to the commentary, and snap away... but do not get off the bus. This is your city tour."