Do some people-watching at College Green. If its paved paths could talk, this historic town square would have some fascinating stories to tell.
You'll be spoiled for sightseeing choice in City Centre Dublin. College Green is a good place to begin here, but there are lots of other fine places to experience. Guinness Storehouse, Trinity College, and Aviva Stadium are not far from the public square and and will cap off your day nicely.