I am headed to Ireland in late May and unfortunately don't think I have enough time to see the Ring of Kerry AND Islands of Aran/ Cliffs of Moher. Which one would you recommend? Also, I was going to cut Dublin out of my trip entirely to save time as well. Is this a mistake? I am traveling with my husband and 1 year old, and we do tend to enjoy scenic places, hikes, and bike rides in beautiful places more than the cities and pubs. As of now, our plan is to fly in and out of Shannon, visit the Dingle peninsula for a few days Killarney National Park for a day, then one of the other two mentioned (Ring of Kerry or Islands of Aran). Thanks so much for your help and suggestions!
Since you are seeing both Killarney National Park and Dingle peninsula I would opt for Aran Islands. The ferry near Galway to Innishmore is such fun. Your 1 y.o. might even enjoy the boat ride. You will also enjoy the hike up the hill to the old fort, Dun Aengus which is right next to the sea.
Cliffs of Mohrer are amazing, but I probably spent an hour or less there.
It's about a 4 hour drive from Dingle to Galway, so you'd be spending half of one day just getting from one place to the other.
Since you'll already be in the Dingle/Killarney area maybe your limited time might be better spent just staying put and exploring more of the ROK, including the Gap of Dunloe, Valencia Island and the Skellig Ring. The Kerry Cliffs may not be quite as dramatic as Moher, but neither are they as crowded.
There's plenty else to see in and around Killarney, especially if your true interests are hiking, biking, and enjoying beautiful scenery.
Since you're flying in and out of Shannon I think that skipping Dublin this trip would be your better option. Sounds like you're a little pinched for time, in which case I'd suggest making the most of it and concentrating on one geographic area - Killarney in this case.
I really enjoyed Aran Islands. Plenty of views of beautiful cliffs there. There really aren’t any protective railings. The people at the visitor center assured me that there aren’t many accidents, but I would only take a 1 year old to a cliff top if I had some sort of “harness/leash” set up for safety.