P R
Google
One of the best museums I've ever visited and a very great addition to going to the national museum. You will see detailed maps, animations, movies, and dioramas of medieval Dublin and how the town formed. Personal narratives and a timeline of its history.
Lots of stuff here, any short video on YouTube you might have watched about this place does not adequately cover all there is here, so not a place you want to come if you're looking for a quick in and out in my opinion.
You can easily spend several hours here if you're actually trying to learn and read all the info, so FYI. You can probably casually walk through in about an hour skipping a lot of the reading, and maybe sticking to visual media, but the reading is where all the details are.
If you want the full experience I would block out two to three hours of your day, and take your time. 2 hours some reading and skipping other parts, maybe up to 3 hours if you read and watch everything.... including short videos and movies. There's a lot of stuff presented to you and it's done extraordinarily well, it's very well put together and in a very modern way.
There's also a nice stair climb to the top of the church tower for a nice view. Don't be afraid it only takes a couple minutes to get up there, take your time if you're slow on stairs... it's very short and a nice view from a top Christ Church cathedral which this museum is a part of.
Has nice clean restrooms and a nice gift shop as well. Hope that is helpful, definitely go here and definitely take your time!