Alouise D.
Yelp
In most countries a post office is just the building where you buy stamps and send mail. Here in Ireland the General Post Office in Dublin (located on O'Connell Street) was the headquarters for the 1916 Easter Rising.
I moved to Dublin (on a temporary 2 year holiday visa) in August 2016. When I got here I saw all these 1916 Easter Rising 100th anniversary banners, and I'll be honest my knowledge of Irish history was lacking. I had no idea what this event was about before I moved here. If you're like me then the GPO Witness History is a great museum to visit to learn about this. To oversimplify (a lot) during Easter week in 1916 a group of men and women took over several major buildings in Dublin to rebel against the British (Ireland was a part of the British Empire at this time). The General Post Office (GPO) was the main headquarters for the Irish leading this Rising. So while on one side of the GPO you can buy stamps and send mail, on the other side you can learn about the history of Ireland.
The GPO Witness History has exhibits about what led up to the Rising, what happened during the Rising, and the aftermath of the Rising. While Ireland didn't become an independent Republic until 1922 the Easter Rising was a catalyst for Ireland's independence.
While people in Ireland are probably well versed in this event if you're a tourist or new to the country you might not be. This is a great place to learn about the Easter Rising. There are artefacts, some interactive exhibits, and videos to watch. There are some short documentaries, but I really recommend watching the main video (in the theatre) that gives a great overview of this event.
The exhibits themselves are well laid out and easy to follow. When you are finished go through the exhibit there's a small cafe/gift shop upstairs. There are also toilet facilities, which were well maintained. The staff at the front desk were helpful in explaining the best way to go through and see everything.
If you check on Groupon they'll sometimes had a deal for the GPO Witness History. I was able to get a general adult admission ticket for €3 on Groupon. If not the regular adult admission is €13 in person or €10 if you book online (lower prices for students/seniors/children). If you're visiting Dublin I think this is included in the Dublin pass as well. Give yourself about an hour or more to go through here.