Hi Scott,
It's great to see that you're planning on visiting this fall, and there are loads of castles and historical places to explore while you're here. :)
Bunratty Castle is open in October, and you can visit the castle and folk park, as well as attend a
medieval banquet! What other castles did you have in mind?
Since you'll be in Dublin, you can visit
Dublin Castle, and many of the other
historical buildings in the county. In Galway there is of course the famous
Kylemore Abbey, among
others. When you're in Kinsale I definitely recommend a trip to
Charles Fort, and of course
Kilkenny Castle in Kilkenny.
These are just a few options, and you can find even more ideas and suggestions in this suggested
castles itinerary. Since you are interested in history, I think you might also like
Ireland's Ancient East, which is filled with ancient tombs and Vikings.
You'll find that there are many museums on the Emerald Isle as well, from the Galway City Museum to the Little Museum of Dublin. You can find some favourites
here. Most will be open all year round, but times and days may differ, so make sure to check their websites before you plan your trip.
I hope this was helpful, and feel free to give me a shout if you have any questions! :)
Warm regards,
Melin