Not to be missed in Dublin?

14 Henrietta Street, https://14henriettastreet.ie."Restored" Georgian townhouse that mirrors the ups and downs of Dublin.

Book of Kells in the Trinity Old Library.

If your tour does not include Brú na Bóinne / Newgrange, then that would be a great day trip pre-tour. The Mary Gibbons tours are excellent.

In Dublin, maybe "not so well known" (but not hidden), is the emigration museum.

I am new to the Forum and second all of the above suggestions. I would tell you to have a look at "20 things to do in Dublin before you go for a feckin' pint" by Colin Murphy and Donal O'Dea for an oddball take on Dublin sights (if you can stand the silly writing style), and a good listing of Dublin pubs, with emphasis on their atmosphere and history. Also "A Feckin' Tour of Ireland" by Colin Murphy & Brendan O'Reilly.

For a book of "hidden/not-so-well-known" experiences, I would recommend "Secret Dublin--An Unusual Guide" by Pol O Conghaile. I love the Stained Glass Room at the Hugh Lane (more Harry Clarke windows at Bewley's Grafton Street Cafe and in Dingle), the Gaiety Theatre hand prints and The Cat and the Rat in the Christ Church crypt. On my list for this summer are The Hungry Tree, the Chester Beatty roof garden (Who knew? I've been to the museum at least a dozen times.), St. Valentine's relics at the Whitefriar Street Church, the Irish Jewish Museum, Iveagh Gardens, the Camino starting point and Marsh's Library in St. Patrick's Close. There seems to be something for everyone in this book and it's pocket-size. But beware the miniscule print. Have fun!

Hello from Wisconsin,
You could do worse than to take a long walk starting with a walk around St. Steven's Green, head down Grafton St. to the sculpture of Molly Malone, then a bit to your right (east) is Trinity College with the Book of Kells and sculpture by Henry Moore under a large American Maple tree, head across the River Liffey and up O'Connell St., the Grand Post Office (GPO) of rebellion fame, with a dodge to the Moore Lane Market, and, the Hewer in the Sewer sculpture and up to the Remembrance Park at the top of O'Connell St. This is South to North, you can do the reverse but the sun, ...ha ha ha, will be in your eyes heading south.

A side trip to Kilmainham Gaol. Interesting jail for so many reasons.

There are many good pubs that need to be attended to.

wayne iNWI

I agree with Brú na Bóinne too. You can sign up for a day tour at the visitor center.

Check out The Connoisseur Experience at the Guinness Storehouse!

St. Patrick's Church is beautiful and nice to visit. After seeing St. Patrick's, my mom and I started walking toward Kilmainham Gaol and came across a lovely little church called St. Audoen's Church. It's the the only remaining medieval parish church in Dublin. It's small, but very interesting. I found it quite moving.

Per the website, it's closed for maintenance for 2021. I don't know when you're visiting Dublin, but if you're going to be near this church, you might want to check if it's opened for visitors. Here's the website: https://heritageireland.ie/visit/places-to-visit/st-audoens-church/#place--opening

Our incredible experience for hearing trad music was at the Cobblestone pub, where we went after our visit to the Kilmainham Gaol.

While seeing and hearing phenomenal drop-in musicians, you can have a “Feckin” pint, but the music was really feckin’ good!

Thanks for all of the responses!!! Don't hesitate to share more...lol. I am liking the learning.