About 10 years ago, a friend and I did an equestrian vacation based at Kinnitty Castle in Offaly County, Ireland. We started in Dublin and took the train to Tullamore for our stay at the castle. We did half-day rides in the Slieve Bloom Mountains, took a falconry class, toured Birr Castle and its gardens, and took the bus to Kildare to see the Irish National Stud. I would love to go back to see more of the country, but we packed a lot into our short trip, including plenty of challenging rides.
Hope that gives you some ideas.