I was in Dublin once for my birthday, more or less passed out in a Queen Ann chair in the lobby of the hotel. I had a lot more fun in villages and towns (particularly Clonmel).
Given your ancestors comes from Dublin, you may be able to track down readily easily.
While I’m reluctant to state it here, but my surname is ‘Fitzpatrick’. One of only two ‘Fitz’ prefix surname to predate the Norman invasion. My ancestors come from near Cavan Town. There is some controversy about this, but in the original Gaelic, Mac Giolla Phádraig (anglicized ‘Fitzpatrick’), means sons of the servants of Saint Patrick.
When I visited Ireland it was before online sources--perhaps some records can be searched more quickly now. Of course a lot were destroyed by the IRA in 1922.