4 days in Ireland

We traveled to Ireland with my teenage nieces last summer. We spent a week on the west coast and 3 days in Dublin. With only 4 days, though, I'd suggest sticking to Dublin and parts around there. Trains and buses might be your best bet, as you'll have to get a decent sized car to fit that many people. Our nieces loved being out in the country out west, seeing the Cliffs of Moher, Bunratty Castle, and the Aran Islands. The biggest hit, though, was shopping. If you have shoppers, hit Grafton Street in Dublin. If you're in Dublin on a Sunday, there's pick-up games of soccer, cricket, and hurling in Phoenix Park. My niece played soccer with a group there, and we watched a bit of a cricket match.

You can't do much in 4 days. I'm assuming you're flying in on day one and out on day four. For a first visit I'd suggest Dublin. The areas I'd suggest you don't miss are Trinity College tour, Book of Kells, Natural History Museum, Kilmainham Goal and, if you're up to it, take your teen on a musical pub tour/crawl which goes into explaining Irish music. If you get a chance, there are early iron age passage tombs north of Dublin - Knowth and Newgrange that are interesting but you'd really want a car for a day to do that. With a car you could also go to Trim Castle for a decent castle ruin. There's plenty of things to keep you busy on a one day drive just north of Dublin. Personally, a four day trip doesn't do Ireland justice.

The natural beauty of Ireland is much more evident in the west, and there are several directions you could go from Shannon airport, or from Cork, in the south. If I personally were going for four days, I would concentrate on a very small area. Just as an example of what's possible, though, on one of my trips, I went straight from Dublin airport to Newgrange, Monasterboice, and spent the night in Navan (all within 45 miles or so of Dublin). The next day I drove around Dublin to the Wicklow Mountains, saw Glendalough, Avoca, and spent the night in Arklow. The following day I drove up the coast road (great scenery!) to Dublin, and spent two nights there, seeing Kilmainham Gaol on the first day, and the Temple Bar area, Merrion Square, the National Museum, and Trinity College on the last day. That kind of plan might work for you. It was a nice mix of city, history, scenery, hiking.

We spent 4 days in Ireland with young adult daughters. We flew into Cork, drove to Kinsale where we spent 2 nights, getting in late afternoon. One day we drove south to Clonakilty and back in a scenic loop and explored a ruined abbey on the way back (I could look it up if you want). Then we drove to Cashel via Cobh (would have liked to spend time there, we just cruised through to see it), stopped at Midleton for the whiskey, and then spent the night at Cashel. Cahir castle was closed (it was winter and it was too icy) but that would have been a great stop, too. We spent the evening & night in Cork, listened to trad music in a pub, flew out the next day. '
It was fun and not too rushed. We had a good mix of scenic drives, ruins, castles, pubs, did a little wandering around the villages. Missed going to Charles Fort in Kinsale due to the early winter closure time, you won't have that problem.