You can't go wrong with a national museum the standard of this one and it can only get better when it's free. So it turns out that the National Museum of Ireland is actually housed in different buildings geographically spread out. This one is specifically for archaeology and antiquity.
This museum is truly amazing, the high quality exhibits, the breadth and depth of information. There's so much in this museum that's excellent that I could've spent an entire day here instead of just 3 hours.
The collection of gold artefacts is astonishing with some of the best examples of gold metal-working I've ever seen especially the gold ribbon bars.
The Battle of Clontarf is another excellent exhibition exploring myths surrounding the battle through exhibits containing Viking and Irish weapons, typical of those used in the battle, hoards of precious silver objects and religious treasures.
Finally the exhibit containing several remains of peat bog men (it's always men) and the circumstanced surrounding their deaths is both astonishing for the preserved bodies and informative for the description analysing the events leading up to their deaths.
Highly recommended and a must for anyone visiting Dublin.