Last Minute Trip Change to Dublin

Consider day trips south to the monastic site at Glendalough, the Wicklow Mtns., and Powerscourt, or north up to Newgrange and the Boyne Valley.
If you want to try something independently there's always the short train ride south to Kilkenny or north up to Belfast.

You basically have 3 full days in Dublin, which you could easily fill with things to see & do right there in the city. The RS guide lists everything with coding for top priority, second tier, etc. Of course, adjust according to your personal interests.

We enjoyed our day tour of the Boyne Valley and Newgrange last March but note sights to see are outside so consider the weather. If you go, also consider spending an hour or so at the National Museum-Archaeology in Dublin. Has many items found in the Boyne Valley and more. Very nice and free. We also loved Belfast, which is a two hour train ride from Dublin, for black taxi tour of the “troubles”, Titanic Experience. Can return to Dublin same day. In Dublin the Kilmainham Gaol would probably be of interest at their age as well as a visit to Guinness? Suggest getting tickets to both in advance online.

With only 3 days, I would concentrate on Dublin itself with possibly some trips out to suburbs like Howth and Dun Laoghaire.

Must sees for me in Dublin are Kilmainham Gaol ( if you can still get tickets ), St Patrick's cathedral, Chester Beatty Library, Book of Kells/Trinity .. I also love just walking around Temple Bar.

Thank you all for your help!

You do have limited time, so I am going to warn you that the Book of Kells is probably not worth your time. I know it is famous. I know it is considered a “must see” by those who claim to know such things. However, it turns out to be an entirely underwhelming experience. Very limited viewing.

I did find my tour of Dublin Castle well worth the time involved.

My single most favorite site from my trip to Ireland was Newgrange. If you have a day that isn't raining, I highly recommend it. I would read up about it before you go.
Kilmainham Gaol is a must.
I wasn't planning on visiting the Book of Kells. But I did visit Trinity College. I went into the book shop and noticed that there was no line for the library room. Ten Euros to see the the library room is definitely worth it. Online photos of the Book of Kells are as good as seeing it in person. But the room is fabulous. Maybe less so if there is a one hour line, but you could get lucky like I did.
Archaeological museum is free and fabulous.
Visit Sweny's Pharmacy for ten minutes. This is where James Joyce bought his lemon soap.

I would definitely stay in Dublin with a day trip to Newgrange.

My faves were Dublinia (it's not just for kids) combined with Christ Church cathedral, Archaeology Museum (free and a wow), St Patrick's Cathedral, enjoying the pubs, including the tourist-filled ones in Temple Bar, and the Dublin Literary Pub Crawl. I also went to excellent plays at the Abbey and the Gate. I missed out on Kilmainham Gaol. If you go, stop in at the Patriot's Inn on the corner.

Hello!

There are lots of interesting options in Dublin, as other posters have mentioned. Some additional Dublin choices that our 21 and 24 year old children enjoyed are some of the historical walking tours, a tour of the Guinness storehouse, and listening to live music at some of the pubs. We especially enjoyed the Celt, the Brazenhead and the Hairy Lemon (where the Commitments movie was filmed). Dublin is very walkable, so it's fun to just explore on foot.

If you wanted to see outside of Dublin, you could plan a day trip, either to the Wicklow mountains, Howth, Belfast (and potentially Giant's Causeway), or the Cliffs of Moher. If you just visited Belfast, you could get there by a very comfortable 2-hour train ride. Howth is also a short train ride. The other options outside Dublin would likely either require a rental car or taking a bus tour. There are also some Game of Thrones tour options for Northern Ireland, if anyone in your family was a fan of that show. Two of our children also went on the Dublin rural pub tour that takes you up to some interesting pubs in the Wicklow mountains. We all had a great time on that tour. Finally, the Book of Kells is actually removed from display until March 2020. I loved seeing it, but the tickets now will only get you into the Long Room at the Trinity Library. Have a great trip!

Hmm, without the Book of Kells, the price may be reduced (it should be), and there won't be long lines. The library was by far my favorite part of that visit, seeing one page of the Book of Kells under glass in dim light was meh, IMO.