My husband and I are planning a trip to Ireland, London, and Scotland this September. We were planning on flying into London and spending 3 nights there and then catching the train to Edinburgh and spending 2 nights there and then flying over to Dublin to spend 4 nights in various places in Ireland and then fly out of Dublin. We originally wanted to spend all our time in Ireland but we never get to travel internationally and want to make the most out of it. Does our plan seem doable? And what are MUST sees in Ireland? We for sure want to see the Cliffs of Moher but are open to other suggestions! Any feedback would be GREATLY appreciated!
If you're already booked for a flight to Dublin, I'd recommend staying there and just day-tripping to scenic spots on the east coast, perhaps Powerscourt, or County Meath and the River Boyne. Plenty of enjoying the Irish demeanor to be done right there.
If you really want to go all the way out to see the Cliffs of Moher, I suggest flying to Shannon and staying a few nights in Doolin, with the hopes that the weather will be fine one evening for a scenic boat cruise.
If it were me, I'd go from Shannon and spend the time in County Kerry.
Although Ireland is relatively small, we toured by bicycle in 2011 so we confined ourselves to just a small part of the western part of Ireland, flying in and out of Shannon and not ever reaching Dublin. We stowed the bikes on Bus Eireann buses and took the bus for longer stretches, and Bus Eireann would be an option for you, too, unless you rented a car (they drive in the left side of the road there, as they do in Scotland and England) or hired a private driver or tour.
On the west coast, the Cliffs of Moher were spectacular, but we minded the signs saying it was private land beyond them, and not to walk past the signs, although scores of other people ignored the signs. On the other hand, people have slipped or been blown over the edge by a sudden gust of wind, and the 500 foot drop would make for a messy landing, so we were content to view the cliffs from the safe observation paths contained within the visitor center grounds. The Burren, a unique landscape a few miles east of the Cliffs, is well worth visiting. Out to sea, west of the Cliffs, the Aran Islands were a "must" for us, but with only 4 days, you may not be able to fit in a visit by either plane or ferry. Farther south in Kilrush, a pub dinner and trad music session at Crotty's was one of the highlights for us.
Still farther south, the Dingle Peninsula, Dingle town, and Skellig Michael off the coast of County Kerry were all must-sees, but again, any of these would take time from Dublin and other points in eastern/southern/north Ireland. Depending on how you're planning on getting around, if you did want to venture west for the Cliffs of Moher and/or other destinations nearby, are you committed to flying in and out of Dublin? Is the Shannon airport a possibility for arriving or departing?
Within the short time described (3, 2, and 4 nights, respectively) you're not likely to get out of the big cities of London and Edinburgh but could do a daytrip or two around Dublin. If the flights are booked, then enjoy that plan. If your flights are not yet booked, then you have a few options. The suggestion to skip Dublin and fly to/from Shannon would be a good way to incorporate some smaller towns and rural scenery in the mix. Other options include adding more days and/or skipping Edinburgh. See a list of Rick's prioritized favorite destinations at http://www.ricksteves.com/europe/ireland.