3 days in Dublin Itinerary Options

I loved Giant's Causeway, it's spectacular. If I'm honest I was underwhelmed by the black cab tour. Our tour guide was not the best. All of it sounds like a lot coming all they way from Dublin. The sun rises at 8:30am and sets at 4pm. In the summer it would seem more manageable.

Hello we used Wild Rover tours for a one day tour of NI back in late Aug and it was a highlight of our time in Ireland. Our black cab guide was amazing.
He told us that in your country(Australia ) you are fined if you don’t vote. He had so much information about the time of the troubles too.
Our guide on the the Wild Rover tour also lived through the troubles and her stories were so interesting

The Giant’s causeway was also a highlight. I can’t imagine someone saying it was not spectacular
We also went to a castle ruin.

I am not sure what it is like in Dec. though. Daylight is so short then. It was a long day

Thanks everyone, that's really helpful!

If you decide not to do the Giants Causeway, it’s easy to take the coach bus to and from Belfast from Dublin. That would allow you to see the city and take a black cab tour. Could be done in a very long day, or you could turn it into an overnight.
We took the Paddywagon bus tour from Belfast to giants causeway. It also included two other stops and worked fine. Some people had been on the bus from Dublin. Not sure if they go in December.

I would suggest taking a train to Belfast, and taking in the Black Cab Tour (two hours) and I strongly recommend the Titanic Museum (the Black Cab tour will pick you up at the train station and drop you off at the Titanic Museum if your request) and St. George's Market (easy walk from the Titanic Museum). You could then hire a driver in Belfast to take you on the Antrim Coast; as others have said Giant's Causeway is a "can't miss" visit; and, you are so close to Carrick-A-Rede Rope Bridge, Royal Portrush Golf Club (British Open rotation site), Dunluce Castle and Bushmill's Distillery all within a very close distance. The driver can drop you off right back at the train station. I've been to Belfast and the Antrim Coast 3 times, and would do it again.

I would skip Galway and stay in Dublin 3 nights and Belfast 3 nights. From Belfast, the GC tour is much more manageable. My take on "must-see" sights is that there are only the sights that YOU must see. You won't be tested or graded on your itinerary, either before or after your trip. To visit Ireland and not see at least one of the amazing natural places seems to me to miss the point, and the GC is one of the easiest to see from the two big cities. If your purpose in going to Galway is to see the Cliffs of Moher, then I would stay there for a couple of nights and see more of the West, rather than doing a day trip.

I found the Black Cab tour a bit canned. I think your driver makes all the difference. I wish I had thought to request a driver with the "other" orientation to my leanings. Not sure that would have helped. We stayed in East Belfast, which is a decidedly Unionist area that is not included in the tour. The tour is very much worth doing, make no mistake. Spending time in Belfast, feeling safe there, seeing the increasing diversity of the community and the economic prosperity really puts it all in perspective.

I was in Dublin 12/26/18-1/4/19, and that week between Christmas and NYE was dead. No one around, nearly everything open and empty. We had EPIC, the Dead Zoo and the history museum mostly to ourselves. We had an apartment, so we weren't affected by restaurant closings.

With so little time in the country and at a time of year when the days are very short, trying to pack too much in will soon become tiresome, IMO.

We only had 6 hours between flights in Dublin on our way to Munich, but wanted a bit of a less tourist crowded taste of Dublin/Ireland. We took a 13 Euro taxi ride instead of the available bus to Swords castle. It was a worthy and fascinating free exploration with only a short walk from a defensive tower built to repel Vikings still standing, and a well that was blessed by a saint in the 500s a.d. . Also one of the friendly docents at the castle recommended a local pub just a half block from the castle on Main Street to get a tasty inexpensive lunch and proper pour without fighting crowds.