I visited with a group of student friends on a university trip to Dublin. The exhibit was high quality, informative both for children and big kids such as ourselves.
Dublinia is wonderfully set out and takes you on a visual journey through the ages from Viking invaders founding Dublin right through to Medieval times. The last floor shows how archaeologists pieced together the history of Dublin. You can experience what it was like to live in a viking's house, walk through a medieval street and medieval market with stalls selling all sorts of oddities.
Lots of activities to keep adults and children entertained. We had lots of fun trying on helmets and viking clothes, throwing 'rotten tomatoes' at waxworks charged for stealing bread and we all stopped to make rubbings of our names in Viking runes.
Although at times the exhibition verged on being a bit cheesy and geared more towards children then adults, we loved it nonetheless. We especially had a belly laugh at the viking waxwork groaning on the toilet- although I can understand some may find him a bit much. We can only deduce that the viking diet was at times lacking in fiber.
For an additional 2 euros you can also visit the Christchurch Cathedral through the exit of Dublonia. We didn't as we ran out of time, but it was great value for money. I'd love to visit again when I'm next in Dublin.