This is "Dublin Castle" and it served as the seat of English power in Ireland for quite some time. It is of Norman design and the surrounding industrial era buildings, such as the Courthouse, were built into it in later times.
A gate going, into the "court" area of the "court house". I found the depiction of Lady Justice, in Ireland, especially ironic:
One of the many things we noticed in Dublin was the vast number of churches and cathedrals that exist. This former cathedral has been turned into the Dublin Tourism center and was near the start of our day long tour of the city.
We went to the Saint James Gate Guinness Brewery, where I learned that the same company that makes "the black stuff" also makes the famed Book of World Records. The apparent purpose: to settle once and for all silly, and odd, pub arguments inspired by "the black stuff".
There is no doubt that Ireland is very green and very beautiful. This was a picturesque garden just outside Dublin Castle. Apparently this beautiful structure was built for the sole purpose of housing the King's Horses. (Can you imagine the tax protests back then?)
Finally, the tallest building in the center of the next photo is a famed hotel on the Liffey (the river running through Dublin) with an all copper roof (hence, the green color). What's notable about it: the top floor is owned by Bono and Edge.
To see a fuller tale of the trip, see my Dad's blog: Allmost Daily PB.